Add m-esr52 at 52.6.0

12 files changed, 5635 insertions, 0 deletions

diff --git a/toolkit/components/jsdownloads/test/unit/.eslintrc.js b/toolkit/components/jsdownloads/test/unit/.eslintrc.js
new file mode 100644
index 000000000..d35787cd2
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/.eslintrc.js
@@ -0,0 +1,7 @@
+"use strict";
+
+module.exports = {
+  "extends": [
+    "../../../../../testing/xpcshell/xpcshell.eslintrc.js"
+  ]
+};
diff --git a/toolkit/components/jsdownloads/test/unit/common_test_Download.js b/toolkit/components/jsdownloads/test/unit/common_test_Download.js
new file mode 100644
index 000000000..42d4c5682
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/common_test_Download.js
@@ -0,0 +1,2432 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * This script is loaded by "test_DownloadCore.js" and "test_DownloadLegacy.js"
+ * with different values of the gUseLegacySaver variable, to apply tests to both
+ * the "copy" and "legacy" saver implementations.
+ */
+
+"use strict";
+
+// Globals
+
+const kDeleteTempFileOnExit = "browser.helperApps.deleteTempFileOnExit";
+
+/**
+ * Creates and starts a new download, using either DownloadCopySaver or
+ * DownloadLegacySaver based on the current test run.
+ *
+ * @return {Promise}
+ * @resolves The newly created Download object.  The download may be in progress
+ *           or already finished.  The promiseDownloadStopped function can be
+ *           used to wait for completion.
+ * @rejects JavaScript exception.
+ */
+function promiseStartDownload(aSourceUrl) {
+  if (gUseLegacySaver) {
+    return promiseStartLegacyDownload(aSourceUrl);
+  }
+
+  return promiseNewDownload(aSourceUrl).then(download => {
+    download.start().catch(() => {});
+    return download;
+  });
+}
+
+/**
+ * Creates and starts a new download, configured to keep partial data, and
+ * returns only when the first part of "interruptible_resumable.txt" has been
+ * saved to disk.  You must call "continueResponses" to allow the interruptible
+ * request to continue.
+ *
+ * This function uses either DownloadCopySaver or DownloadLegacySaver based on
+ * the current test run.
+ *
+ * @return {Promise}
+ * @resolves The newly created Download object, still in progress.
+ * @rejects JavaScript exception.
+ */
+function promiseStartDownload_tryToKeepPartialData() {
+  return Task.spawn(function* () {
+    mustInterruptResponses();
+
+    // Start a new download and configure it to keep partially downloaded data.
+    let download;
+    if (!gUseLegacySaver) {
+      let targetFilePath = getTempFile(TEST_TARGET_FILE_NAME).path;
+      download = yield Downloads.createDownload({
+        source: httpUrl("interruptible_resumable.txt"),
+        target: { path: targetFilePath,
+                  partFilePath: targetFilePath + ".part" },
+      });
+      download.tryToKeepPartialData = true;
+      download.start().catch(() => {});
+    } else {
+      // Start a download using nsIExternalHelperAppService, that is configured
+      // to keep partially downloaded data by default.
+      download = yield promiseStartExternalHelperAppServiceDownload();
+    }
+
+    yield promiseDownloadMidway(download);
+    yield promisePartFileReady(download);
+
+    return download;
+  });
+}
+
+/**
+ * This function should be called after the progress notification for a download
+ * is received, and waits for the worker thread of BackgroundFileSaver to
+ * receive the data to be written to the ".part" file on disk.
+ *
+ * @return {Promise}
+ * @resolves When the ".part" file has been written to disk.
+ * @rejects JavaScript exception.
+ */
+function promisePartFileReady(aDownload) {
+  return Task.spawn(function* () {
+    // We don't have control over the file output code in BackgroundFileSaver.
+    // After we receive the download progress notification, we may only check
+    // that the ".part" file has been created, while its size cannot be
+    // determined because the file is currently open.
+    try {
+      do {
+        yield promiseTimeout(50);
+      } while (!(yield OS.File.exists(aDownload.target.partFilePath)));
+    } catch (ex) {
+      if (!(ex instanceof OS.File.Error)) {
+        throw ex;
+      }
+      // This indicates that the file has been created and cannot be accessed.
+      // The specific error might vary with the platform.
+      do_print("Expected exception while checking existence: " + ex.toString());
+      // Wait some more time to allow the write to complete.
+      yield promiseTimeout(100);
+    }
+  });
+}
+
+/**
+ * Checks that the actual data written to disk matches the expected data as well
+ * as the properties of the given DownloadTarget object.
+ *
+ * @param downloadTarget
+ *        The DownloadTarget object whose details have to be verified.
+ * @param expectedContents
+ *        String containing the octets that are expected in the file.
+ *
+ * @return {Promise}
+ * @resolves When the properties have been verified.
+ * @rejects JavaScript exception.
+ */
+var promiseVerifyTarget = Task.async(function* (downloadTarget,
+                                                expectedContents) {
+  yield promiseVerifyContents(downloadTarget.path, expectedContents);
+  do_check_true(downloadTarget.exists);
+  do_check_eq(downloadTarget.size, expectedContents.length);
+});
+
+/**
+ * Waits for an attempt to launch a file, and returns the nsIMIMEInfo used for
+ * the launch, or null if the file was launched with the default handler.
+ */
+function waitForFileLaunched() {
+  return new Promise(resolve => {
+    let waitFn = base => ({
+      launchFile(file, mimeInfo) {
+        Integration.downloads.unregister(waitFn);
+        if (!mimeInfo ||
+            mimeInfo.preferredAction == Ci.nsIMIMEInfo.useSystemDefault) {
+          resolve(null);
+        } else {
+          resolve(mimeInfo);
+        }
+        return Promise.resolve();
+      },
+    });
+    Integration.downloads.register(waitFn);
+  });
+}
+
+/**
+ * Waits for an attempt to show the directory where a file is located, and
+ * returns the path of the file.
+ */
+function waitForDirectoryShown() {
+  return new Promise(resolve => {
+    let waitFn = base => ({
+      showContainingDirectory(path) {
+        Integration.downloads.unregister(waitFn);
+        resolve(path);
+        return Promise.resolve();
+      },
+    });
+    Integration.downloads.register(waitFn);
+  });
+}
+
+// Tests
+
+/**
+ * Executes a download and checks its basic properties after construction.
+ * The download is started by constructing the simplest Download object with
+ * the "copy" saver, or using the legacy nsITransfer interface.
+ */
+add_task(function* test_basic()
+{
+  let targetFile = getTempFile(TEST_TARGET_FILE_NAME);
+
+  let download;
+  if (!gUseLegacySaver) {
+    // When testing DownloadCopySaver, we have control over the download, thus
+    // we can check its basic properties before it starts.
+    download = yield Downloads.createDownload({
+      source: { url: httpUrl("source.txt") },
+      target: { path: targetFile.path },
+      saver: { type: "copy" },
+    });
+
+    do_check_eq(download.source.url, httpUrl("source.txt"));
+    do_check_eq(download.target.path, targetFile.path);
+
+    yield download.start();
+  } else {
+    // When testing DownloadLegacySaver, the download is already started when it
+    // is created, thus we must check its basic properties while in progress.
+    download = yield promiseStartLegacyDownload(null,
+                                                { targetFile: targetFile });
+
+    do_check_eq(download.source.url, httpUrl("source.txt"));
+    do_check_eq(download.target.path, targetFile.path);
+
+    yield promiseDownloadStopped(download);
+  }
+
+  // Check additional properties on the finished download.
+  do_check_true(download.source.referrer === null);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT);
+});
+
+/**
+ * Executes a download with the tryToKeepPartialData property set, and ensures
+ * that the file is saved correctly.  When testing DownloadLegacySaver, the
+ * download is executed using the nsIExternalHelperAppService component.
+ */
+add_task(function* test_basic_tryToKeepPartialData()
+{
+  let download = yield promiseStartDownload_tryToKeepPartialData();
+  continueResponses();
+  yield promiseDownloadStopped(download);
+
+  // The target file should now have been created, and the ".part" file deleted.
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+  do_check_eq(32, download.saver.getSha256Hash().length);
+});
+
+/**
+ * Tests the permissions of the final target file once the download finished.
+ */
+add_task(function* test_unix_permissions()
+{
+  // This test is only executed on some Desktop systems.
+  if (Services.appinfo.OS != "Darwin" && Services.appinfo.OS != "Linux" &&
+      Services.appinfo.OS != "WINNT") {
+    do_print("Skipping test.");
+    return;
+  }
+
+  let launcherPath = getTempFile("app-launcher").path;
+
+  for (let autoDelete of [false, true]) {
+    for (let isPrivate of [false, true]) {
+      for (let launchWhenSucceeded of [false, true]) {
+        do_print("Checking " + JSON.stringify({ autoDelete,
+                                                isPrivate,
+                                                launchWhenSucceeded }));
+
+        Services.prefs.setBoolPref(kDeleteTempFileOnExit, autoDelete);
+
+        let download;
+        if (!gUseLegacySaver) {
+          download = yield Downloads.createDownload({
+            source: { url: httpUrl("source.txt"), isPrivate },
+            target: getTempFile(TEST_TARGET_FILE_NAME).path,
+            launchWhenSucceeded,
+            launcherPath,
+          });
+          yield download.start();
+        } else {
+          download = yield promiseStartLegacyDownload(httpUrl("source.txt"), {
+            isPrivate,
+            launchWhenSucceeded,
+            launcherPath: launchWhenSucceeded && launcherPath,
+          });
+          yield promiseDownloadStopped(download);
+        }
+
+        let isTemporary = launchWhenSucceeded && (autoDelete || isPrivate);
+        let stat = yield OS.File.stat(download.target.path);
+        if (Services.appinfo.OS == "WINNT") {
+          // On Windows
+          // Temporary downloads should be read-only
+          do_check_eq(stat.winAttributes.readOnly, isTemporary ? true : false);
+        } else {
+          // On Linux, Mac
+          // Temporary downloads should be read-only and not accessible to other
+          // users, while permanently downloaded files should be readable and
+          // writable as specified by the system umask.
+          do_check_eq(stat.unixMode,
+                      isTemporary ? 0o400 : (0o666 & ~OS.Constants.Sys.umask));
+        }
+      }
+    }
+  }
+
+  // Clean up the changes to the preference.
+  Services.prefs.clearUserPref(kDeleteTempFileOnExit);
+});
+
+/**
+ * Checks the referrer for downloads.
+ */
+add_task(function* test_referrer()
+{
+  let sourcePath = "/test_referrer.txt";
+  let sourceUrl = httpUrl("test_referrer.txt");
+  let targetPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+
+  function cleanup() {
+    gHttpServer.registerPathHandler(sourcePath, null);
+  }
+  do_register_cleanup(cleanup);
+
+  gHttpServer.registerPathHandler(sourcePath, function (aRequest, aResponse) {
+    aResponse.setHeader("Content-Type", "text/plain", false);
+
+    do_check_true(aRequest.hasHeader("Referer"));
+    do_check_eq(aRequest.getHeader("Referer"), TEST_REFERRER_URL);
+  });
+  let download = yield Downloads.createDownload({
+    source: { url: sourceUrl, referrer: TEST_REFERRER_URL },
+    target: targetPath,
+  });
+  do_check_eq(download.source.referrer, TEST_REFERRER_URL);
+  yield download.start();
+
+  download = yield Downloads.createDownload({
+    source: { url: sourceUrl, referrer: TEST_REFERRER_URL,
+              isPrivate: true },
+    target: targetPath,
+  });
+  do_check_eq(download.source.referrer, TEST_REFERRER_URL);
+  yield download.start();
+
+  // Test the download still works for non-HTTP channel with referrer.
+  sourceUrl = "data:text/html,<html><body></body></html>";
+  download = yield Downloads.createDownload({
+    source: { url: sourceUrl, referrer: TEST_REFERRER_URL },
+    target: targetPath,
+  });
+  do_check_eq(download.source.referrer, TEST_REFERRER_URL);
+  yield download.start();
+
+  cleanup();
+});
+
+/**
+ * Checks the adjustChannel callback for downloads.
+ */
+add_task(function* test_adjustChannel()
+{
+  const sourcePath = "/test_post.txt";
+  const sourceUrl = httpUrl("test_post.txt");
+  const targetPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+  const customHeader = { name: "X-Answer", value: "42" };
+  const postData = "Don't Panic";
+
+  function cleanup() {
+    gHttpServer.registerPathHandler(sourcePath, null);
+  }
+  do_register_cleanup(cleanup);
+
+  gHttpServer.registerPathHandler(sourcePath, aRequest => {
+    do_check_eq(aRequest.method, "POST");
+
+    do_check_true(aRequest.hasHeader(customHeader.name));
+    do_check_eq(aRequest.getHeader(customHeader.name), customHeader.value);
+
+    const stream = aRequest.bodyInputStream;
+    const body = NetUtil.readInputStreamToString(stream, stream.available());
+    do_check_eq(body, postData);
+  });
+
+  function adjustChannel(channel) {
+    channel.QueryInterface(Ci.nsIHttpChannel);
+    channel.setRequestHeader(customHeader.name, customHeader.value, false);
+
+    const stream = Cc["@mozilla.org/io/string-input-stream;1"]
+                   .createInstance(Ci.nsIStringInputStream);
+    stream.setData(postData, postData.length);
+
+    channel.QueryInterface(Ci.nsIUploadChannel2);
+    channel.explicitSetUploadStream(stream, null, -1, "POST", false);
+
+    return Promise.resolve();
+  }
+
+  const download = yield Downloads.createDownload({
+    source: { url: sourceUrl, adjustChannel },
+    target: targetPath,
+  });
+  do_check_eq(download.source.adjustChannel, adjustChannel);
+  do_check_eq(download.toSerializable(), null);
+  yield download.start();
+
+  cleanup();
+});
+
+/**
+ * Checks initial and final state and progress for a successful download.
+ */
+add_task(function* test_initial_final_state()
+{
+  let download;
+  if (!gUseLegacySaver) {
+    // When testing DownloadCopySaver, we have control over the download, thus
+    // we can check its state before it starts.
+    download = yield promiseNewDownload();
+
+    do_check_true(download.stopped);
+    do_check_false(download.succeeded);
+    do_check_false(download.canceled);
+    do_check_true(download.error === null);
+    do_check_eq(download.progress, 0);
+    do_check_true(download.startTime === null);
+    do_check_false(download.target.exists);
+    do_check_eq(download.target.size, 0);
+
+    yield download.start();
+  } else {
+    // When testing DownloadLegacySaver, the download is already started when it
+    // is created, thus we cannot check its initial state.
+    download = yield promiseStartLegacyDownload();
+    yield promiseDownloadStopped(download);
+  }
+
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+  do_check_eq(download.progress, 100);
+  do_check_true(isValidDate(download.startTime));
+  do_check_true(download.target.exists);
+  do_check_eq(download.target.size, TEST_DATA_SHORT.length);
+});
+
+/**
+ * Checks the notification of the final download state.
+ */
+add_task(function* test_final_state_notified()
+{
+  mustInterruptResponses();
+
+  let download = yield promiseStartDownload(httpUrl("interruptible.txt"));
+
+  let onchangeNotified = false;
+  let lastNotifiedStopped;
+  let lastNotifiedProgress;
+  download.onchange = function () {
+    onchangeNotified = true;
+    lastNotifiedStopped = download.stopped;
+    lastNotifiedProgress = download.progress;
+  };
+
+  // Allow the download to complete.
+  let promiseAttempt = download.start();
+  continueResponses();
+  yield promiseAttempt;
+
+  // The view should have been notified before the download completes.
+  do_check_true(onchangeNotified);
+  do_check_true(lastNotifiedStopped);
+  do_check_eq(lastNotifiedProgress, 100);
+});
+
+/**
+ * Checks intermediate progress for a successful download.
+ */
+add_task(function* test_intermediate_progress()
+{
+  mustInterruptResponses();
+
+  let download = yield promiseStartDownload(httpUrl("interruptible.txt"));
+
+  yield promiseDownloadMidway(download);
+
+  do_check_true(download.hasProgress);
+  do_check_eq(download.currentBytes, TEST_DATA_SHORT.length);
+  do_check_eq(download.totalBytes, TEST_DATA_SHORT.length * 2);
+
+  // The final file size should not be computed for in-progress downloads.
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+
+  // Continue after the first chunk of data is fully received.
+  continueResponses();
+  yield promiseDownloadStopped(download);
+
+  do_check_true(download.stopped);
+  do_check_eq(download.progress, 100);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+});
+
+/**
+ * Downloads a file with a "Content-Length" of 0 and checks the progress.
+ */
+add_task(function* test_empty_progress()
+{
+  let download = yield promiseStartDownload(httpUrl("empty.txt"));
+  yield promiseDownloadStopped(download);
+
+  do_check_true(download.stopped);
+  do_check_true(download.hasProgress);
+  do_check_eq(download.progress, 100);
+  do_check_eq(download.currentBytes, 0);
+  do_check_eq(download.totalBytes, 0);
+
+  // We should have received the content type even for an empty file.
+  do_check_eq(download.contentType, "text/plain");
+
+  do_check_eq((yield OS.File.stat(download.target.path)).size, 0);
+  do_check_true(download.target.exists);
+  do_check_eq(download.target.size, 0);
+});
+
+/**
+ * Downloads a file with a "Content-Length" of 0 with the tryToKeepPartialData
+ * property set, and ensures that the file is saved correctly.
+ */
+add_task(function* test_empty_progress_tryToKeepPartialData()
+{
+  // Start a new download and configure it to keep partially downloaded data.
+  let download;
+  if (!gUseLegacySaver) {
+    let targetFilePath = getTempFile(TEST_TARGET_FILE_NAME).path;
+    download = yield Downloads.createDownload({
+      source: httpUrl("empty.txt"),
+      target: { path: targetFilePath,
+                partFilePath: targetFilePath + ".part" },
+    });
+    download.tryToKeepPartialData = true;
+    download.start().catch(() => {});
+  } else {
+    // Start a download using nsIExternalHelperAppService, that is configured
+    // to keep partially downloaded data by default.
+    download = yield promiseStartExternalHelperAppServiceDownload(
+                                                         httpUrl("empty.txt"));
+  }
+  yield promiseDownloadStopped(download);
+
+  // The target file should now have been created, and the ".part" file deleted.
+  do_check_eq((yield OS.File.stat(download.target.path)).size, 0);
+  do_check_true(download.target.exists);
+  do_check_eq(download.target.size, 0);
+
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+  do_check_eq(32, download.saver.getSha256Hash().length);
+});
+
+/**
+ * Downloads an empty file with no "Content-Length" and checks the progress.
+ */
+add_task(function* test_empty_noprogress()
+{
+  let sourcePath = "/test_empty_noprogress.txt";
+  let sourceUrl = httpUrl("test_empty_noprogress.txt");
+  let deferRequestReceived = Promise.defer();
+
+  // Register an interruptible handler that notifies us when the request occurs.
+  function cleanup() {
+    gHttpServer.registerPathHandler(sourcePath, null);
+  }
+  do_register_cleanup(cleanup);
+
+  registerInterruptibleHandler(sourcePath,
+    function firstPart(aRequest, aResponse) {
+      aResponse.setHeader("Content-Type", "text/plain", false);
+      deferRequestReceived.resolve();
+    }, function secondPart(aRequest, aResponse) { });
+
+  // Start the download, without allowing the request to finish.
+  mustInterruptResponses();
+  let download;
+  if (!gUseLegacySaver) {
+    // When testing DownloadCopySaver, we have control over the download, thus
+    // we can hook its onchange callback that will be notified when the
+    // download starts.
+    download = yield promiseNewDownload(sourceUrl);
+
+    download.onchange = function () {
+      if (!download.stopped) {
+        do_check_false(download.hasProgress);
+        do_check_eq(download.currentBytes, 0);
+        do_check_eq(download.totalBytes, 0);
+      }
+    };
+
+    download.start().catch(() => {});
+  } else {
+    // When testing DownloadLegacySaver, the download is already started when it
+    // is created, and it may have already made all needed property change
+    // notifications, thus there is no point in checking the onchange callback.
+    download = yield promiseStartLegacyDownload(sourceUrl);
+  }
+
+  // Wait for the request to be received by the HTTP server, but don't allow the
+  // request to finish yet.  Before checking the download state, wait for the
+  // events to be processed by the client.
+  yield deferRequestReceived.promise;
+  yield promiseExecuteSoon();
+
+  // Check that this download has no progress report.
+  do_check_false(download.stopped);
+  do_check_false(download.hasProgress);
+  do_check_eq(download.currentBytes, 0);
+  do_check_eq(download.totalBytes, 0);
+
+  // Now allow the response to finish.
+  continueResponses();
+  yield promiseDownloadStopped(download);
+
+  // We should have received the content type even if no progress is reported.
+  do_check_eq(download.contentType, "text/plain");
+
+  // Verify the state of the completed download.
+  do_check_true(download.stopped);
+  do_check_false(download.hasProgress);
+  do_check_eq(download.progress, 100);
+  do_check_eq(download.currentBytes, 0);
+  do_check_eq(download.totalBytes, 0);
+  do_check_true(download.target.exists);
+  do_check_eq(download.target.size, 0);
+
+  do_check_eq((yield OS.File.stat(download.target.path)).size, 0);
+});
+
+/**
+ * Calls the "start" method two times before the download is finished.
+ */
+add_task(function* test_start_twice()
+{
+  mustInterruptResponses();
+
+  let download;
+  if (!gUseLegacySaver) {
+    // When testing DownloadCopySaver, we have control over the download, thus
+    // we can start the download later during the test.
+    download = yield promiseNewDownload(httpUrl("interruptible.txt"));
+  } else {
+    // When testing DownloadLegacySaver, the download is already started when it
+    // is created.  Effectively, we are starting the download three times.
+    download = yield promiseStartLegacyDownload(httpUrl("interruptible.txt"));
+  }
+
+  // Call the start method two times.
+  let promiseAttempt1 = download.start();
+  let promiseAttempt2 = download.start();
+
+  // Allow the download to finish.
+  continueResponses();
+
+  // Both promises should now be resolved.
+  yield promiseAttempt1;
+  yield promiseAttempt2;
+
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+});
+
+/**
+ * Cancels a download and verifies that its state is reported correctly.
+ */
+add_task(function* test_cancel_midway()
+{
+  mustInterruptResponses();
+
+  // In this test case, we execute different checks that are only possible with
+  // DownloadCopySaver or DownloadLegacySaver respectively.
+  let download;
+  let options = {};
+  if (!gUseLegacySaver) {
+    download = yield promiseNewDownload(httpUrl("interruptible.txt"));
+  } else {
+    download = yield promiseStartLegacyDownload(httpUrl("interruptible.txt"),
+                                                options);
+  }
+
+  // Cancel the download after receiving the first part of the response.
+  let deferCancel = Promise.defer();
+  let onchange = function () {
+    if (!download.stopped && !download.canceled && download.progress == 50) {
+      // Cancel the download immediately during the notification.
+      deferCancel.resolve(download.cancel());
+
+      // The state change happens immediately after calling "cancel", but
+      // temporary files or part files may still exist at this point.
+      do_check_true(download.canceled);
+    }
+  };
+
+  // Register for the notification, but also call the function directly in
+  // case the download already reached the expected progress.  This may happen
+  // when using DownloadLegacySaver.
+  download.onchange = onchange;
+  onchange();
+
+  let promiseAttempt;
+  if (!gUseLegacySaver) {
+    promiseAttempt = download.start();
+  }
+
+  // Wait on the promise returned by the "cancel" method to ensure that the
+  // cancellation process finished and temporary files were removed.
+  yield deferCancel.promise;
+
+  if (gUseLegacySaver) {
+    // The nsIWebBrowserPersist instance should have been canceled now.
+    do_check_eq(options.outPersist.result, Cr.NS_ERROR_ABORT);
+  }
+
+  do_check_true(download.stopped);
+  do_check_true(download.canceled);
+  do_check_true(download.error === null);
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+
+  do_check_false(yield OS.File.exists(download.target.path));
+
+  // Progress properties are not reset by canceling.
+  do_check_eq(download.progress, 50);
+  do_check_eq(download.totalBytes, TEST_DATA_SHORT.length * 2);
+  do_check_eq(download.currentBytes, TEST_DATA_SHORT.length);
+
+  if (!gUseLegacySaver) {
+    // The promise returned by "start" should have been rejected meanwhile.
+    try {
+      yield promiseAttempt;
+      do_throw("The download should have been canceled.");
+    } catch (ex) {
+      if (!(ex instanceof Downloads.Error)) {
+        throw ex;
+      }
+      do_check_false(ex.becauseSourceFailed);
+      do_check_false(ex.becauseTargetFailed);
+    }
+  }
+});
+
+/**
+ * Cancels a download while keeping partially downloaded data, and verifies that
+ * both the target file and the ".part" file are deleted.
+ */
+add_task(function* test_cancel_midway_tryToKeepPartialData()
+{
+  let download = yield promiseStartDownload_tryToKeepPartialData();
+
+  do_check_true(yield OS.File.exists(download.target.path));
+  do_check_true(yield OS.File.exists(download.target.partFilePath));
+
+  yield download.cancel();
+  yield download.removePartialData();
+
+  do_check_true(download.stopped);
+  do_check_true(download.canceled);
+  do_check_true(download.error === null);
+
+  do_check_false(yield OS.File.exists(download.target.path));
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+});
+
+/**
+ * Cancels a download right after starting it.
+ */
+add_task(function* test_cancel_immediately()
+{
+  mustInterruptResponses();
+
+  let download = yield promiseStartDownload(httpUrl("interruptible.txt"));
+
+  let promiseAttempt = download.start();
+  do_check_false(download.stopped);
+
+  let promiseCancel = download.cancel();
+  do_check_true(download.canceled);
+
+  // At this point, we don't know whether the download has already stopped or
+  // is still waiting for cancellation.  We can wait on the promise returned
+  // by the "start" method to know for sure.
+  try {
+    yield promiseAttempt;
+    do_throw("The download should have been canceled.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error)) {
+      throw ex;
+    }
+    do_check_false(ex.becauseSourceFailed);
+    do_check_false(ex.becauseTargetFailed);
+  }
+
+  do_check_true(download.stopped);
+  do_check_true(download.canceled);
+  do_check_true(download.error === null);
+
+  do_check_false(yield OS.File.exists(download.target.path));
+
+  // Check that the promise returned by the "cancel" method has been resolved.
+  yield promiseCancel;
+});
+
+/**
+ * Cancels and restarts a download sequentially.
+ */
+add_task(function* test_cancel_midway_restart()
+{
+  mustInterruptResponses();
+
+  let download = yield promiseStartDownload(httpUrl("interruptible.txt"));
+
+  // The first time, cancel the download midway.
+  yield promiseDownloadMidway(download);
+  yield download.cancel();
+
+  do_check_true(download.stopped);
+
+  // The second time, we'll provide the entire interruptible response.
+  continueResponses();
+  download.onchange = null;
+  let promiseAttempt = download.start();
+
+  // Download state should have already been reset.
+  do_check_false(download.stopped);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+
+  // For the following test, we rely on the network layer reporting its progress
+  // asynchronously.  Otherwise, there is nothing stopping the restarted
+  // download from reaching the same progress as the first request already.
+  do_check_eq(download.progress, 0);
+  do_check_eq(download.totalBytes, 0);
+  do_check_eq(download.currentBytes, 0);
+
+  yield promiseAttempt;
+
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+});
+
+/**
+ * Cancels a download and restarts it from where it stopped.
+ */
+add_task(function* test_cancel_midway_restart_tryToKeepPartialData()
+{
+  let download = yield promiseStartDownload_tryToKeepPartialData();
+  yield download.cancel();
+
+  do_check_true(download.stopped);
+  do_check_true(download.hasPartialData);
+
+  // The target file should not exist, but we should have kept the partial data.
+  do_check_false(yield OS.File.exists(download.target.path));
+  yield promiseVerifyContents(download.target.partFilePath, TEST_DATA_SHORT);
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+
+  // Verify that the server sent the response from the start.
+  do_check_eq(gMostRecentFirstBytePos, 0);
+
+  // The second time, we'll request and obtain the second part of the response,
+  // but we still stop when half of the remaining progress is reached.
+  let deferMidway = Promise.defer();
+  download.onchange = function () {
+    if (!download.stopped && !download.canceled &&
+        download.currentBytes == Math.floor(TEST_DATA_SHORT.length * 3 / 2)) {
+      download.onchange = null;
+      deferMidway.resolve();
+    }
+  };
+
+  mustInterruptResponses();
+  let promiseAttempt = download.start();
+
+  // Continue when the number of bytes we received is correct, then check that
+  // progress is at about 75 percent.  The exact figure may vary because of
+  // rounding issues, since the total number of bytes in the response might not
+  // be a multiple of four.
+  yield deferMidway.promise;
+  do_check_true(download.progress > 72 && download.progress < 78);
+
+  // Now we allow the download to finish.
+  continueResponses();
+  yield promiseAttempt;
+
+  // Check that the server now sent the second part only.
+  do_check_eq(gMostRecentFirstBytePos, TEST_DATA_SHORT.length);
+
+  // The target file should now have been created, and the ".part" file deleted.
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+});
+
+/**
+ * Cancels a download while keeping partially downloaded data, then removes the
+ * data and restarts the download from the beginning.
+ */
+add_task(function* test_cancel_midway_restart_removePartialData()
+{
+  let download = yield promiseStartDownload_tryToKeepPartialData();
+  yield download.cancel();
+
+  do_check_true(download.hasPartialData);
+  yield promiseVerifyContents(download.target.partFilePath, TEST_DATA_SHORT);
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+
+  yield download.removePartialData();
+
+  do_check_false(download.hasPartialData);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+
+  // The second time, we'll request and obtain the entire response again.
+  continueResponses();
+  yield download.start();
+
+  // Verify that the server sent the response from the start.
+  do_check_eq(gMostRecentFirstBytePos, 0);
+
+  // The target file should now have been created, and the ".part" file deleted.
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+});
+
+/**
+ * Cancels a download while keeping partially downloaded data, then removes the
+ * data and restarts the download from the beginning without keeping the partial
+ * data anymore.
+ */
+add_task(function* test_cancel_midway_restart_tryToKeepPartialData_false()
+{
+  let download = yield promiseStartDownload_tryToKeepPartialData();
+  yield download.cancel();
+
+  download.tryToKeepPartialData = false;
+
+  // The above property change does not affect existing partial data.
+  do_check_true(download.hasPartialData);
+  yield promiseVerifyContents(download.target.partFilePath, TEST_DATA_SHORT);
+
+  yield download.removePartialData();
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+
+  // Restart the download from the beginning.
+  mustInterruptResponses();
+  download.start().catch(() => {});
+
+  yield promiseDownloadMidway(download);
+  yield promisePartFileReady(download);
+
+  // While the download is in progress, we should still have a ".part" file.
+  do_check_false(download.hasPartialData);
+  do_check_true(yield OS.File.exists(download.target.partFilePath));
+
+  // On Unix, verify that the file with the partially downloaded data is not
+  // accessible by other users on the system.
+  if (Services.appinfo.OS == "Darwin" || Services.appinfo.OS == "Linux") {
+    do_check_eq((yield OS.File.stat(download.target.partFilePath)).unixMode,
+                0o600);
+  }
+
+  yield download.cancel();
+
+  // The ".part" file should be deleted now that the download is canceled.
+  do_check_false(download.hasPartialData);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+
+  // The third time, we'll request and obtain the entire response again.
+  continueResponses();
+  yield download.start();
+
+  // Verify that the server sent the response from the start.
+  do_check_eq(gMostRecentFirstBytePos, 0);
+
+  // The target file should now have been created, and the ".part" file deleted.
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+});
+
+/**
+ * Cancels a download right after starting it, then restarts it immediately.
+ */
+add_task(function* test_cancel_immediately_restart_immediately()
+{
+  mustInterruptResponses();
+
+  let download = yield promiseStartDownload(httpUrl("interruptible.txt"));
+  let promiseAttempt = download.start();
+
+  do_check_false(download.stopped);
+
+  download.cancel();
+  do_check_true(download.canceled);
+
+  let promiseRestarted = download.start();
+  do_check_false(download.stopped);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+
+  // For the following test, we rely on the network layer reporting its progress
+  // asynchronously.  Otherwise, there is nothing stopping the restarted
+  // download from reaching the same progress as the first request already.
+  do_check_eq(download.hasProgress, false);
+  do_check_eq(download.progress, 0);
+  do_check_eq(download.totalBytes, 0);
+  do_check_eq(download.currentBytes, 0);
+
+  // Ensure the next request is now allowed to complete, regardless of whether
+  // the canceled request was received by the server or not.
+  continueResponses();
+  try {
+    yield promiseAttempt;
+    // If we get here, it means that the first attempt actually succeeded.  In
+    // fact, this could be a valid outcome, because the cancellation request may
+    // not have been processed in time before the download finished.
+    do_print("The download should have been canceled.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error)) {
+      throw ex;
+    }
+    do_check_false(ex.becauseSourceFailed);
+    do_check_false(ex.becauseTargetFailed);
+  }
+
+  yield promiseRestarted;
+
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+});
+
+/**
+ * Cancels a download midway, then restarts it immediately.
+ */
+add_task(function* test_cancel_midway_restart_immediately()
+{
+  mustInterruptResponses();
+
+  let download = yield promiseStartDownload(httpUrl("interruptible.txt"));
+  let promiseAttempt = download.start();
+
+  // The first time, cancel the download midway.
+  yield promiseDownloadMidway(download);
+  download.cancel();
+  do_check_true(download.canceled);
+
+  let promiseRestarted = download.start();
+  do_check_false(download.stopped);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+
+  // For the following test, we rely on the network layer reporting its progress
+  // asynchronously.  Otherwise, there is nothing stopping the restarted
+  // download from reaching the same progress as the first request already.
+  do_check_eq(download.hasProgress, false);
+  do_check_eq(download.progress, 0);
+  do_check_eq(download.totalBytes, 0);
+  do_check_eq(download.currentBytes, 0);
+
+  // The second request is allowed to complete.
+  continueResponses();
+  try {
+    yield promiseAttempt;
+    do_throw("The download should have been canceled.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error)) {
+      throw ex;
+    }
+    do_check_false(ex.becauseSourceFailed);
+    do_check_false(ex.becauseTargetFailed);
+  }
+
+  yield promiseRestarted;
+
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+});
+
+/**
+ * Calls the "cancel" method on a successful download.
+ */
+add_task(function* test_cancel_successful()
+{
+  let download = yield promiseStartDownload();
+  yield promiseDownloadStopped(download);
+
+  // The cancel method should succeed with no effect.
+  yield download.cancel();
+
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT);
+});
+
+/**
+ * Calls the "cancel" method two times in a row.
+ */
+add_task(function* test_cancel_twice()
+{
+  mustInterruptResponses();
+
+  let download = yield promiseStartDownload(httpUrl("interruptible.txt"));
+
+  let promiseAttempt = download.start();
+  do_check_false(download.stopped);
+
+  let promiseCancel1 = download.cancel();
+  do_check_true(download.canceled);
+  let promiseCancel2 = download.cancel();
+
+  try {
+    yield promiseAttempt;
+    do_throw("The download should have been canceled.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error)) {
+      throw ex;
+    }
+    do_check_false(ex.becauseSourceFailed);
+    do_check_false(ex.becauseTargetFailed);
+  }
+
+  // Both promises should now be resolved.
+  yield promiseCancel1;
+  yield promiseCancel2;
+
+  do_check_true(download.stopped);
+  do_check_false(download.succeeded);
+  do_check_true(download.canceled);
+  do_check_true(download.error === null);
+
+  do_check_false(yield OS.File.exists(download.target.path));
+});
+
+/**
+ * Checks the "refresh" method for succeeded downloads.
+ */
+add_task(function* test_refresh_succeeded()
+{
+  let download = yield promiseStartDownload();
+  yield promiseDownloadStopped(download);
+
+  // The DownloadTarget properties should be the same after calling "refresh".
+  yield download.refresh();
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT);
+
+  // If the file is removed, only the "exists" property should change, and the
+  // "size" property should keep its previous value.
+  yield OS.File.move(download.target.path, download.target.path + ".old");
+  yield download.refresh();
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, TEST_DATA_SHORT.length);
+
+  // The DownloadTarget properties should be restored when the file is put back.
+  yield OS.File.move(download.target.path + ".old", download.target.path);
+  yield download.refresh();
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT);
+});
+
+/**
+ * Checks that a download cannot be restarted after the "finalize" method.
+ */
+add_task(function* test_finalize()
+{
+  mustInterruptResponses();
+
+  let download = yield promiseStartDownload(httpUrl("interruptible.txt"));
+
+  let promiseFinalized = download.finalize();
+
+  try {
+    yield download.start();
+    do_throw("It should not be possible to restart after finalization.");
+  } catch (ex) { }
+
+  yield promiseFinalized;
+
+  do_check_true(download.stopped);
+  do_check_false(download.succeeded);
+  do_check_true(download.canceled);
+  do_check_true(download.error === null);
+
+  do_check_false(yield OS.File.exists(download.target.path));
+});
+
+/**
+ * Checks that the "finalize" method can remove partially downloaded data.
+ */
+add_task(function* test_finalize_tryToKeepPartialData()
+{
+  // Check finalization without removing partial data.
+  let download = yield promiseStartDownload_tryToKeepPartialData();
+  yield download.finalize();
+
+  do_check_true(download.hasPartialData);
+  do_check_true(yield OS.File.exists(download.target.partFilePath));
+
+  // Clean up.
+  yield download.removePartialData();
+
+  // Check finalization while removing partial data.
+  download = yield promiseStartDownload_tryToKeepPartialData();
+  yield download.finalize(true);
+
+  do_check_false(download.hasPartialData);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+});
+
+/**
+ * Checks that whenSucceeded returns a promise that is resolved after a restart.
+ */
+add_task(function* test_whenSucceeded_after_restart()
+{
+  mustInterruptResponses();
+
+  let promiseSucceeded;
+
+  let download;
+  if (!gUseLegacySaver) {
+    // When testing DownloadCopySaver, we have control over the download, thus
+    // we can verify getting a reference before the first download attempt.
+    download = yield promiseNewDownload(httpUrl("interruptible.txt"));
+    promiseSucceeded = download.whenSucceeded();
+    download.start().catch(() => {});
+  } else {
+    // When testing DownloadLegacySaver, the download is already started when it
+    // is created, thus we cannot get the reference before the first attempt.
+    download = yield promiseStartLegacyDownload(httpUrl("interruptible.txt"));
+    promiseSucceeded = download.whenSucceeded();
+  }
+
+  // Cancel the first download attempt.
+  yield download.cancel();
+
+  // The second request is allowed to complete.
+  continueResponses();
+  download.start().catch(() => {});
+
+  // Wait for the download to finish by waiting on the whenSucceeded promise.
+  yield promiseSucceeded;
+
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+});
+
+/**
+ * Ensures download error details are reported on network failures.
+ */
+add_task(function* test_error_source()
+{
+  let serverSocket = startFakeServer();
+  try {
+    let sourceUrl = "http://localhost:" + serverSocket.port + "/source.txt";
+
+    let download;
+    try {
+      if (!gUseLegacySaver) {
+        // When testing DownloadCopySaver, we want to check that the promise
+        // returned by the "start" method is rejected.
+        download = yield promiseNewDownload(sourceUrl);
+
+        do_check_true(download.error === null);
+
+        yield download.start();
+      } else {
+        // When testing DownloadLegacySaver, we cannot be sure whether we are
+        // testing the promise returned by the "start" method or we are testing
+        // the "error" property checked by promiseDownloadStopped.  This happens
+        // because we don't have control over when the download is started.
+        download = yield promiseStartLegacyDownload(sourceUrl);
+        yield promiseDownloadStopped(download);
+      }
+      do_throw("The download should have failed.");
+    } catch (ex) {
+      if (!(ex instanceof Downloads.Error) || !ex.becauseSourceFailed) {
+        throw ex;
+      }
+      // A specific error object is thrown when reading from the source fails.
+    }
+
+    // Check the properties now that the download stopped.
+    do_check_true(download.stopped);
+    do_check_false(download.canceled);
+    do_check_true(download.error !== null);
+    do_check_true(download.error.becauseSourceFailed);
+    do_check_false(download.error.becauseTargetFailed);
+
+    do_check_false(yield OS.File.exists(download.target.path));
+    do_check_false(download.target.exists);
+    do_check_eq(download.target.size, 0);
+  } finally {
+    serverSocket.close();
+  }
+});
+
+/**
+ * Ensures a download error is reported when receiving less bytes than what was
+ * specified in the Content-Length header.
+ */
+add_task(function* test_error_source_partial()
+{
+  let sourceUrl = httpUrl("shorter-than-content-length-http-1-1.txt");
+
+  let enforcePref = Services.prefs.getBoolPref("network.http.enforce-framing.http1");
+  Services.prefs.setBoolPref("network.http.enforce-framing.http1", true);
+
+  function cleanup() {
+    Services.prefs.setBoolPref("network.http.enforce-framing.http1", enforcePref);
+  }
+  do_register_cleanup(cleanup);
+
+  let download;
+  try {
+    if (!gUseLegacySaver) {
+      // When testing DownloadCopySaver, we want to check that the promise
+      // returned by the "start" method is rejected.
+      download = yield promiseNewDownload(sourceUrl);
+
+      do_check_true(download.error === null);
+
+      yield download.start();
+    } else {
+      // When testing DownloadLegacySaver, we cannot be sure whether we are
+      // testing the promise returned by the "start" method or we are testing
+      // the "error" property checked by promiseDownloadStopped.  This happens
+      // because we don't have control over when the download is started.
+      download = yield promiseStartLegacyDownload(sourceUrl);
+      yield promiseDownloadStopped(download);
+    }
+    do_throw("The download should have failed.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error) || !ex.becauseSourceFailed) {
+      throw ex;
+    }
+    // A specific error object is thrown when reading from the source fails.
+  }
+
+  // Check the properties now that the download stopped.
+  do_check_true(download.stopped);
+  do_check_false(download.canceled);
+  do_check_true(download.error !== null);
+  do_check_true(download.error.becauseSourceFailed);
+  do_check_false(download.error.becauseTargetFailed);
+  do_check_eq(download.error.result, Cr.NS_ERROR_NET_PARTIAL_TRANSFER);
+
+  do_check_false(yield OS.File.exists(download.target.path));
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+});
+
+/**
+ * Ensures download error details are reported on local writing failures.
+ */
+add_task(function* test_error_target()
+{
+  // Create a file without write access permissions before downloading.
+  let targetFile = getTempFile(TEST_TARGET_FILE_NAME);
+  targetFile.create(Ci.nsIFile.NORMAL_FILE_TYPE, 0);
+  try {
+    let download;
+    try {
+      if (!gUseLegacySaver) {
+        // When testing DownloadCopySaver, we want to check that the promise
+        // returned by the "start" method is rejected.
+        download = yield Downloads.createDownload({
+          source: httpUrl("source.txt"),
+          target: targetFile,
+        });
+        yield download.start();
+      } else {
+        // When testing DownloadLegacySaver, we cannot be sure whether we are
+        // testing the promise returned by the "start" method or we are testing
+        // the "error" property checked by promiseDownloadStopped.  This happens
+        // because we don't have control over when the download is started.
+        download = yield promiseStartLegacyDownload(null,
+                                                    { targetFile: targetFile });
+        yield promiseDownloadStopped(download);
+      }
+      do_throw("The download should have failed.");
+    } catch (ex) {
+      if (!(ex instanceof Downloads.Error) || !ex.becauseTargetFailed) {
+        throw ex;
+      }
+      // A specific error object is thrown when writing to the target fails.
+    }
+
+    // Check the properties now that the download stopped.
+    do_check_true(download.stopped);
+    do_check_false(download.canceled);
+    do_check_true(download.error !== null);
+    do_check_true(download.error.becauseTargetFailed);
+    do_check_false(download.error.becauseSourceFailed);
+  } finally {
+    // Restore the default permissions to allow deleting the file on Windows.
+    if (targetFile.exists()) {
+      targetFile.permissions = FileUtils.PERMS_FILE;
+      targetFile.remove(false);
+    }
+  }
+});
+
+/**
+ * Restarts a failed download.
+ */
+add_task(function* test_error_restart()
+{
+  let download;
+
+  // Create a file without write access permissions before downloading.
+  let targetFile = getTempFile(TEST_TARGET_FILE_NAME);
+  targetFile.create(Ci.nsIFile.NORMAL_FILE_TYPE, 0);
+  try {
+    // Use DownloadCopySaver or DownloadLegacySaver based on the test run,
+    // specifying the target file we created.
+    if (!gUseLegacySaver) {
+      download = yield Downloads.createDownload({
+        source: httpUrl("source.txt"),
+        target: targetFile,
+      });
+      download.start().catch(() => {});
+    } else {
+      download = yield promiseStartLegacyDownload(null,
+                                                  { targetFile: targetFile });
+    }
+    yield promiseDownloadStopped(download);
+    do_throw("The download should have failed.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error) || !ex.becauseTargetFailed) {
+      throw ex;
+    }
+    // A specific error object is thrown when writing to the target fails.
+  } finally {
+    // Restore the default permissions to allow deleting the file on Windows.
+    if (targetFile.exists()) {
+      targetFile.permissions = FileUtils.PERMS_FILE;
+
+      // Also for Windows, rename the file before deleting.  This makes the
+      // current file name available immediately for a new file, while deleting
+      // in place prevents creation of a file with the same name for some time.
+      targetFile.moveTo(null, targetFile.leafName + ".delete.tmp");
+      targetFile.remove(false);
+    }
+  }
+
+  // Restart the download and wait for completion.
+  yield download.start();
+
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.canceled);
+  do_check_true(download.error === null);
+  do_check_eq(download.progress, 100);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT);
+});
+
+/**
+ * Executes download in both public and private modes.
+ */
+add_task(function* test_public_and_private()
+{
+  let sourcePath = "/test_public_and_private.txt";
+  let sourceUrl = httpUrl("test_public_and_private.txt");
+  let testCount = 0;
+
+  // Apply pref to allow all cookies.
+  Services.prefs.setIntPref("network.cookie.cookieBehavior", 0);
+
+  function cleanup() {
+    Services.prefs.clearUserPref("network.cookie.cookieBehavior");
+    Services.cookies.removeAll();
+    gHttpServer.registerPathHandler(sourcePath, null);
+  }
+  do_register_cleanup(cleanup);
+
+  gHttpServer.registerPathHandler(sourcePath, function (aRequest, aResponse) {
+    aResponse.setHeader("Content-Type", "text/plain", false);
+
+    if (testCount == 0) {
+      // No cookies should exist for first public download.
+      do_check_false(aRequest.hasHeader("Cookie"));
+      aResponse.setHeader("Set-Cookie", "foobar=1", false);
+      testCount++;
+    } else if (testCount == 1) {
+      // The cookie should exists for second public download.
+      do_check_true(aRequest.hasHeader("Cookie"));
+      do_check_eq(aRequest.getHeader("Cookie"), "foobar=1");
+      testCount++;
+    } else if (testCount == 2)  {
+      // No cookies should exist for first private download.
+      do_check_false(aRequest.hasHeader("Cookie"));
+    }
+  });
+
+  let targetFile = getTempFile(TEST_TARGET_FILE_NAME);
+  yield Downloads.fetch(sourceUrl, targetFile);
+  yield Downloads.fetch(sourceUrl, targetFile);
+
+  if (!gUseLegacySaver) {
+    let download = yield Downloads.createDownload({
+      source: { url: sourceUrl, isPrivate: true },
+      target: targetFile,
+    });
+    yield download.start();
+  } else {
+    let download = yield promiseStartLegacyDownload(sourceUrl,
+                                                    { isPrivate: true });
+    yield promiseDownloadStopped(download);
+  }
+
+  cleanup();
+});
+
+/**
+ * Checks the startTime gets updated even after a restart.
+ */
+add_task(function* test_cancel_immediately_restart_and_check_startTime()
+{
+  let download = yield promiseStartDownload();
+
+  let startTime = download.startTime;
+  do_check_true(isValidDate(download.startTime));
+
+  yield download.cancel();
+  do_check_eq(download.startTime.getTime(), startTime.getTime());
+
+  // Wait for a timeout.
+  yield promiseTimeout(10);
+
+  yield download.start();
+  do_check_true(download.startTime.getTime() > startTime.getTime());
+});
+
+/**
+ * Executes download with content-encoding.
+ */
+add_task(function* test_with_content_encoding()
+{
+  let sourcePath = "/test_with_content_encoding.txt";
+  let sourceUrl = httpUrl("test_with_content_encoding.txt");
+
+  function cleanup() {
+    gHttpServer.registerPathHandler(sourcePath, null);
+  }
+  do_register_cleanup(cleanup);
+
+  gHttpServer.registerPathHandler(sourcePath, function (aRequest, aResponse) {
+    aResponse.setHeader("Content-Type", "text/plain", false);
+    aResponse.setHeader("Content-Encoding", "gzip", false);
+    aResponse.setHeader("Content-Length",
+                        "" + TEST_DATA_SHORT_GZIP_ENCODED.length, false);
+
+    let bos = new BinaryOutputStream(aResponse.bodyOutputStream);
+    bos.writeByteArray(TEST_DATA_SHORT_GZIP_ENCODED,
+                       TEST_DATA_SHORT_GZIP_ENCODED.length);
+  });
+
+  let download = yield promiseStartDownload(sourceUrl);
+  yield promiseDownloadStopped(download);
+
+  do_check_eq(download.progress, 100);
+  do_check_eq(download.totalBytes, TEST_DATA_SHORT_GZIP_ENCODED.length);
+
+  // Ensure the content matches the decoded test data.
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT);
+
+  cleanup();
+});
+
+/**
+ * Checks that the file is not decoded if the extension matches the encoding.
+ */
+add_task(function* test_with_content_encoding_ignore_extension()
+{
+  let sourcePath = "/test_with_content_encoding_ignore_extension.gz";
+  let sourceUrl = httpUrl("test_with_content_encoding_ignore_extension.gz");
+
+  function cleanup() {
+    gHttpServer.registerPathHandler(sourcePath, null);
+  }
+  do_register_cleanup(cleanup);
+
+  gHttpServer.registerPathHandler(sourcePath, function (aRequest, aResponse) {
+    aResponse.setHeader("Content-Type", "text/plain", false);
+    aResponse.setHeader("Content-Encoding", "gzip", false);
+    aResponse.setHeader("Content-Length",
+                        "" + TEST_DATA_SHORT_GZIP_ENCODED.length, false);
+
+    let bos = new BinaryOutputStream(aResponse.bodyOutputStream);
+    bos.writeByteArray(TEST_DATA_SHORT_GZIP_ENCODED,
+                       TEST_DATA_SHORT_GZIP_ENCODED.length);
+  });
+
+  let download = yield promiseStartDownload(sourceUrl);
+  yield promiseDownloadStopped(download);
+
+  do_check_eq(download.progress, 100);
+  do_check_eq(download.totalBytes, TEST_DATA_SHORT_GZIP_ENCODED.length);
+  do_check_eq(download.target.size, TEST_DATA_SHORT_GZIP_ENCODED.length);
+
+  // Ensure the content matches the encoded test data.  We convert the data to a
+  // string before executing the content check.
+  yield promiseVerifyTarget(download.target,
+        String.fromCharCode.apply(String, TEST_DATA_SHORT_GZIP_ENCODED));
+
+  cleanup();
+});
+
+/**
+ * Cancels and restarts a download sequentially with content-encoding.
+ */
+add_task(function* test_cancel_midway_restart_with_content_encoding()
+{
+  mustInterruptResponses();
+
+  let download = yield promiseStartDownload(httpUrl("interruptible_gzip.txt"));
+
+  // The first time, cancel the download midway.
+  let deferCancel = Promise.defer();
+  let onchange = function () {
+    if (!download.stopped && !download.canceled &&
+        download.currentBytes == TEST_DATA_SHORT_GZIP_ENCODED_FIRST.length) {
+      deferCancel.resolve(download.cancel());
+    }
+  };
+
+  // Register for the notification, but also call the function directly in
+  // case the download already reached the expected progress.
+  download.onchange = onchange;
+  onchange();
+
+  yield deferCancel.promise;
+
+  do_check_true(download.stopped);
+
+  // The second time, we'll provide the entire interruptible response.
+  continueResponses();
+  download.onchange = null;
+  yield download.start();
+
+  do_check_eq(download.progress, 100);
+  do_check_eq(download.totalBytes, TEST_DATA_SHORT_GZIP_ENCODED.length);
+
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT);
+});
+
+/**
+ * Download with parental controls enabled.
+ */
+add_task(function* test_blocked_parental_controls()
+{
+  let blockFn = base => ({
+    shouldBlockForParentalControls: () => Promise.resolve(true),
+  });
+
+  Integration.downloads.register(blockFn);
+  function cleanup() {
+    Integration.downloads.unregister(blockFn);
+  }
+  do_register_cleanup(cleanup);
+
+  let download;
+  try {
+    if (!gUseLegacySaver) {
+      // When testing DownloadCopySaver, we want to check that the promise
+      // returned by the "start" method is rejected.
+      download = yield promiseNewDownload();
+      yield download.start();
+    } else {
+      // When testing DownloadLegacySaver, we cannot be sure whether we are
+      // testing the promise returned by the "start" method or we are testing
+      // the "error" property checked by promiseDownloadStopped.  This happens
+      // because we don't have control over when the download is started.
+      download = yield promiseStartLegacyDownload();
+      yield promiseDownloadStopped(download);
+    }
+    do_throw("The download should have blocked.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error) || !ex.becauseBlocked) {
+      throw ex;
+    }
+    do_check_true(ex.becauseBlockedByParentalControls);
+    do_check_true(download.error.becauseBlockedByParentalControls);
+  }
+
+  // Now that the download stopped, the target file should not exist.
+  do_check_false(yield OS.File.exists(download.target.path));
+
+  cleanup();
+});
+
+/**
+ * Test a download that will be blocked by Windows parental controls by
+ * resulting in an HTTP status code of 450.
+ */
+add_task(function* test_blocked_parental_controls_httpstatus450()
+{
+  let download;
+  try {
+    if (!gUseLegacySaver) {
+      download = yield promiseNewDownload(httpUrl("parentalblocked.zip"));
+      yield download.start();
+    }
+    else {
+      download = yield promiseStartLegacyDownload(httpUrl("parentalblocked.zip"));
+      yield promiseDownloadStopped(download);
+    }
+    do_throw("The download should have blocked.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error) || !ex.becauseBlocked) {
+      throw ex;
+    }
+    do_check_true(ex.becauseBlockedByParentalControls);
+    do_check_true(download.error.becauseBlockedByParentalControls);
+    do_check_true(download.stopped);
+  }
+
+  do_check_false(yield OS.File.exists(download.target.path));
+});
+
+/**
+ * Download with runtime permissions
+ */
+add_task(function* test_blocked_runtime_permissions()
+{
+  let blockFn = base => ({
+    shouldBlockForRuntimePermissions: () => Promise.resolve(true),
+  });
+
+  Integration.downloads.register(blockFn);
+  function cleanup() {
+    Integration.downloads.unregister(blockFn);
+  }
+  do_register_cleanup(cleanup);
+
+  let download;
+  try {
+    if (!gUseLegacySaver) {
+      // When testing DownloadCopySaver, we want to check that the promise
+      // returned by the "start" method is rejected.
+      download = yield promiseNewDownload();
+      yield download.start();
+    } else {
+      // When testing DownloadLegacySaver, we cannot be sure whether we are
+      // testing the promise returned by the "start" method or we are testing
+      // the "error" property checked by promiseDownloadStopped.  This happens
+      // because we don't have control over when the download is started.
+      download = yield promiseStartLegacyDownload();
+      yield promiseDownloadStopped(download);
+    }
+    do_throw("The download should have blocked.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error) || !ex.becauseBlocked) {
+      throw ex;
+    }
+    do_check_true(ex.becauseBlockedByRuntimePermissions);
+    do_check_true(download.error.becauseBlockedByRuntimePermissions);
+  }
+
+  // Now that the download stopped, the target file should not exist.
+  do_check_false(yield OS.File.exists(download.target.path));
+
+  cleanup();
+});
+
+/**
+ * Check that DownloadCopySaver can always retrieve the hash.
+ * DownloadLegacySaver can only retrieve the hash when
+ * nsIExternalHelperAppService is invoked.
+ */
+add_task(function* test_getSha256Hash()
+{
+  if (!gUseLegacySaver) {
+    let download = yield promiseStartDownload(httpUrl("source.txt"));
+    yield promiseDownloadStopped(download);
+    do_check_true(download.stopped);
+    do_check_eq(32, download.saver.getSha256Hash().length);
+  }
+});
+
+/**
+ * Create a download which will be reputation blocked.
+ *
+ * @param options
+ *        {
+ *           keepPartialData: bool,
+ *           keepBlockedData: bool,
+ *        }
+ * @return {Promise}
+ * @resolves The reputation blocked download.
+ * @rejects JavaScript exception.
+ */
+var promiseBlockedDownload = Task.async(function* (options) {
+  let blockFn = base => ({
+    shouldBlockForReputationCheck: () => Promise.resolve({
+      shouldBlock: true,
+      verdict: Downloads.Error.BLOCK_VERDICT_UNCOMMON,
+    }),
+    shouldKeepBlockedData: () => Promise.resolve(options.keepBlockedData),
+  });
+
+  Integration.downloads.register(blockFn);
+  function cleanup() {
+    Integration.downloads.unregister(blockFn);
+  }
+  do_register_cleanup(cleanup);
+
+  let download;
+
+  try {
+    if (options.keepPartialData) {
+      download = yield promiseStartDownload_tryToKeepPartialData();
+      continueResponses();
+    } else if (gUseLegacySaver) {
+      download = yield promiseStartLegacyDownload();
+    } else {
+      download = yield promiseNewDownload();
+      yield download.start();
+      do_throw("The download should have blocked.");
+    }
+
+    yield promiseDownloadStopped(download);
+    do_throw("The download should have blocked.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error) || !ex.becauseBlocked) {
+      throw ex;
+    }
+    do_check_true(ex.becauseBlockedByReputationCheck);
+    do_check_eq(ex.reputationCheckVerdict,
+                Downloads.Error.BLOCK_VERDICT_UNCOMMON);
+    do_check_true(download.error.becauseBlockedByReputationCheck);
+    do_check_eq(download.error.reputationCheckVerdict,
+                Downloads.Error.BLOCK_VERDICT_UNCOMMON);
+  }
+
+  do_check_true(download.stopped);
+  do_check_false(download.succeeded);
+  do_check_false(yield OS.File.exists(download.target.path));
+
+  cleanup();
+  return download;
+});
+
+/**
+ * Checks that application reputation blocks the download and the target file
+ * does not exist.
+ */
+add_task(function* test_blocked_applicationReputation()
+{
+  let download = yield promiseBlockedDownload({
+    keepPartialData: false,
+    keepBlockedData: false,
+  });
+
+  // Now that the download is blocked, the target file should not exist.
+  do_check_false(yield OS.File.exists(download.target.path));
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+
+  // There should also be no blocked data in this case
+  do_check_false(download.hasBlockedData);
+});
+
+/**
+ * Checks that if a download restarts while processing an application reputation
+ * request, the status is handled correctly.
+ */
+add_task(function* test_blocked_applicationReputation_race()
+{
+  let isFirstShouldBlockCall = true;
+
+  let blockFn = base => ({
+    shouldBlockForReputationCheck(download) {
+      if (isFirstShouldBlockCall) {
+        isFirstShouldBlockCall = false;
+
+        // 2. Cancel and restart the download before the first attempt has a
+        //    chance to finish.
+        download.cancel();
+        download.removePartialData();
+        download.start();
+
+        // 3. Allow the first attempt to finish with a blocked response.
+        return Promise.resolve({
+          shouldBlock: true,
+          verdict: Downloads.Error.BLOCK_VERDICT_UNCOMMON,
+        });
+      }
+
+      // 4/5. Don't block the download the second time. The race condition would
+      //      occur with the first attempt regardless of whether the second one
+      //      is blocked, but not blocking here makes the test simpler.
+      return Promise.resolve({
+        shouldBlock: false,
+        verdict: "",
+      });
+    },
+    shouldKeepBlockedData: () => Promise.resolve(true),
+  });
+
+  Integration.downloads.register(blockFn);
+  function cleanup() {
+    Integration.downloads.unregister(blockFn);
+  }
+  do_register_cleanup(cleanup);
+
+  let download;
+
+  try {
+    // 1. Start the download and get a reference to the promise asociated with
+    //    the first attempt, before allowing the response to continue.
+    download = yield promiseStartDownload_tryToKeepPartialData();
+    let firstAttempt = promiseDownloadStopped(download);
+    continueResponses();
+
+    // 4/5. Wait for the first attempt to be completed. The result of this
+    //      should appear as a cancellation.
+    yield firstAttempt;
+
+    do_throw("The first attempt should have been canceled.");
+  } catch (ex) {
+    // The "becauseBlocked" property should be false.
+    if (!(ex instanceof Downloads.Error) || ex.becauseBlocked) {
+      throw ex;
+    }
+  }
+
+  // 6. Wait for the second attempt to be completed.
+  yield promiseDownloadStopped(download);
+
+  // 7. At this point, "hasBlockedData" should be false.
+  do_check_false(download.hasBlockedData);
+
+  cleanup();
+});
+
+/**
+ * Checks that application reputation blocks the download but maintains the
+ * blocked data, which will be deleted when the block is confirmed.
+ */
+add_task(function* test_blocked_applicationReputation_confirmBlock()
+{
+  let download = yield promiseBlockedDownload({
+    keepPartialData: true,
+    keepBlockedData: true,
+  });
+
+  do_check_true(download.hasBlockedData);
+  do_check_true(yield OS.File.exists(download.target.partFilePath));
+
+  yield download.confirmBlock();
+
+  // After confirming the block the download should be in a failed state and
+  // have no downloaded data left on disk.
+  do_check_true(download.stopped);
+  do_check_false(download.succeeded);
+  do_check_false(download.hasBlockedData);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+  do_check_false(yield OS.File.exists(download.target.path));
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+});
+
+/**
+ * Checks that application reputation blocks the download but maintains the
+ * blocked data, which will be used to complete the download when unblocking.
+ */
+add_task(function* test_blocked_applicationReputation_unblock()
+{
+  let download = yield promiseBlockedDownload({
+    keepPartialData: true,
+    keepBlockedData: true,
+  });
+
+  do_check_true(download.hasBlockedData);
+  do_check_true(yield OS.File.exists(download.target.partFilePath));
+
+  yield download.unblock();
+
+  // After unblocking the download should have succeeded and be
+  // present at the final path.
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.hasBlockedData);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+  yield promiseVerifyTarget(download.target, TEST_DATA_SHORT + TEST_DATA_SHORT);
+
+  // The only indication the download was previously blocked is the
+  // existence of the error, so we make sure it's still set.
+  do_check_true(download.error instanceof Downloads.Error);
+  do_check_true(download.error.becauseBlocked);
+  do_check_true(download.error.becauseBlockedByReputationCheck);
+});
+
+/**
+ * Check that calling cancel on a blocked download will not cause errors
+ */
+add_task(function* test_blocked_applicationReputation_cancel()
+{
+  let download = yield promiseBlockedDownload({
+    keepPartialData: true,
+    keepBlockedData: true,
+  });
+
+  // This call should succeed on a blocked download.
+  yield download.cancel();
+
+  // Calling cancel should not have changed the current state, the download
+  // should still be blocked.
+  do_check_true(download.error.becauseBlockedByReputationCheck);
+  do_check_true(download.stopped);
+  do_check_false(download.succeeded);
+  do_check_true(download.hasBlockedData);
+});
+
+/**
+ * Checks that unblock and confirmBlock cannot race on a blocked download
+ */
+add_task(function* test_blocked_applicationReputation_decisionRace()
+{
+  let download = yield promiseBlockedDownload({
+    keepPartialData: true,
+    keepBlockedData: true,
+  });
+
+  let unblockPromise = download.unblock();
+  let confirmBlockPromise = download.confirmBlock();
+
+  yield confirmBlockPromise.then(() => {
+    do_throw("confirmBlock should have failed.");
+  }, () => {});
+
+  yield unblockPromise;
+
+  // After unblocking the download should have succeeded and be
+  // present at the final path.
+  do_check_true(download.stopped);
+  do_check_true(download.succeeded);
+  do_check_false(download.hasBlockedData);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+  do_check_true(yield OS.File.exists(download.target.path));
+
+  download = yield promiseBlockedDownload({
+    keepPartialData: true,
+    keepBlockedData: true,
+  });
+
+  confirmBlockPromise = download.confirmBlock();
+  unblockPromise = download.unblock();
+
+  yield unblockPromise.then(() => {
+    do_throw("unblock should have failed.");
+  }, () => {});
+
+  yield confirmBlockPromise;
+
+  // After confirming the block the download should be in a failed state and
+  // have no downloaded data left on disk.
+  do_check_true(download.stopped);
+  do_check_false(download.succeeded);
+  do_check_false(download.hasBlockedData);
+  do_check_false(yield OS.File.exists(download.target.partFilePath));
+  do_check_false(yield OS.File.exists(download.target.path));
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+});
+
+/**
+ * Checks that unblocking a blocked download fails if the blocked data has been
+ * removed.
+ */
+add_task(function* test_blocked_applicationReputation_unblock()
+{
+  let download = yield promiseBlockedDownload({
+    keepPartialData: true,
+    keepBlockedData: true,
+  });
+
+  do_check_true(download.hasBlockedData);
+  do_check_true(yield OS.File.exists(download.target.partFilePath));
+
+  // Remove the blocked data without telling the download.
+  yield OS.File.remove(download.target.partFilePath);
+
+  let unblockPromise = download.unblock();
+  yield unblockPromise.then(() => {
+    do_throw("unblock should have failed.");
+  }, () => {});
+
+  // Even though unblocking failed the download state should have been updated
+  // to reflect the lack of blocked data.
+  do_check_false(download.hasBlockedData);
+  do_check_true(download.stopped);
+  do_check_false(download.succeeded);
+  do_check_false(download.target.exists);
+  do_check_eq(download.target.size, 0);
+});
+
+/**
+ * download.showContainingDirectory() action
+ */
+add_task(function* test_showContainingDirectory() {
+  let targetPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+
+  let download = yield Downloads.createDownload({
+    source: { url: httpUrl("source.txt") },
+    target: ""
+  });
+
+  let promiseDirectoryShown = waitForDirectoryShown();
+  yield download.showContainingDirectory();
+  let path = yield promiseDirectoryShown;
+  try {
+    new FileUtils.File(path);
+    do_throw("Should have failed because of an invalid path.");
+  } catch (ex) {
+    if (!(ex instanceof Components.Exception)) {
+      throw ex;
+    }
+    // Invalid paths on Windows are reported with NS_ERROR_FAILURE,
+    // but with NS_ERROR_FILE_UNRECOGNIZED_PATH on Mac/Linux
+    let validResult = ex.result == Cr.NS_ERROR_FILE_UNRECOGNIZED_PATH ||
+                      ex.result == Cr.NS_ERROR_FAILURE;
+    do_check_true(validResult);
+  }
+
+  download = yield Downloads.createDownload({
+    source: { url: httpUrl("source.txt") },
+    target: targetPath
+  });
+
+  promiseDirectoryShown = waitForDirectoryShown();
+  download.showContainingDirectory();
+  yield promiseDirectoryShown;
+});
+
+/**
+ * download.launch() action
+ */
+add_task(function* test_launch() {
+  let customLauncher = getTempFile("app-launcher");
+
+  // Test both with and without setting a custom application.
+  for (let launcherPath of [null, customLauncher.path]) {
+    let download;
+    if (!gUseLegacySaver) {
+      // When testing DownloadCopySaver, we have control over the download, thus
+      // we can test that file is not launched if download.succeeded is not set.
+      download = yield Downloads.createDownload({
+        source: httpUrl("source.txt"),
+        target: getTempFile(TEST_TARGET_FILE_NAME).path,
+        launcherPath: launcherPath,
+        launchWhenSucceeded: true
+      });
+
+      try {
+        yield download.launch();
+        do_throw("Can't launch download file as it has not completed yet");
+      } catch (ex) {
+        do_check_eq(ex.message,
+                    "launch can only be called if the download succeeded");
+      }
+
+      yield download.start();
+    } else {
+      // When testing DownloadLegacySaver, the download is already started when
+      // it is created, thus we don't test calling "launch" before starting.
+      download = yield promiseStartLegacyDownload(
+                                         httpUrl("source.txt"),
+                                         { launcherPath: launcherPath,
+                                           launchWhenSucceeded: true });
+      yield promiseDownloadStopped(download);
+    }
+
+    do_check_true(download.launchWhenSucceeded);
+
+    let promiseFileLaunched = waitForFileLaunched();
+    download.launch();
+    let result = yield promiseFileLaunched;
+
+    // Verify that the results match the test case.
+    if (!launcherPath) {
+      // This indicates that the default handler has been chosen.
+      do_check_true(result === null);
+    } else {
+      // Check the nsIMIMEInfo instance that would have been used for launching.
+      do_check_eq(result.preferredAction, Ci.nsIMIMEInfo.useHelperApp);
+      do_check_true(result.preferredApplicationHandler
+                          .QueryInterface(Ci.nsILocalHandlerApp)
+                          .executable.equals(customLauncher));
+    }
+  }
+});
+
+/**
+ * Test passing an invalid path as the launcherPath property.
+ */
+add_task(function* test_launcherPath_invalid() {
+  let download = yield Downloads.createDownload({
+    source: { url: httpUrl("source.txt") },
+    target: { path: getTempFile(TEST_TARGET_FILE_NAME).path },
+    launcherPath: " "
+  });
+
+  let promiseDownloadLaunched = new Promise(resolve => {
+    let waitFn = base => ({
+      __proto__: base,
+      launchDownload() {
+        Integration.downloads.unregister(waitFn);
+        let superPromise = super.launchDownload(...arguments);
+        resolve(superPromise);
+        return superPromise;
+      },
+    });
+    Integration.downloads.register(waitFn);
+  });
+
+  yield download.start();
+  try {
+    download.launch();
+    yield promiseDownloadLaunched;
+    do_throw("Can't launch file with invalid custom launcher")
+  } catch (ex) {
+    if (!(ex instanceof Components.Exception)) {
+      throw ex;
+    }
+    // Invalid paths on Windows are reported with NS_ERROR_FAILURE,
+    // but with NS_ERROR_FILE_UNRECOGNIZED_PATH on Mac/Linux
+    let validResult = ex.result == Cr.NS_ERROR_FILE_UNRECOGNIZED_PATH ||
+                      ex.result == Cr.NS_ERROR_FAILURE;
+    do_check_true(validResult);
+  }
+});
+
+/**
+ * Tests that download.launch() is automatically called after
+ * the download finishes if download.launchWhenSucceeded = true
+ */
+add_task(function* test_launchWhenSucceeded() {
+  let customLauncher = getTempFile("app-launcher");
+
+  // Test both with and without setting a custom application.
+  for (let launcherPath of [null, customLauncher.path]) {
+    let promiseFileLaunched = waitForFileLaunched();
+
+    if (!gUseLegacySaver) {
+      let download = yield Downloads.createDownload({
+        source: httpUrl("source.txt"),
+        target: getTempFile(TEST_TARGET_FILE_NAME).path,
+        launchWhenSucceeded: true,
+        launcherPath: launcherPath,
+      });
+      yield download.start();
+    } else {
+      let download = yield promiseStartLegacyDownload(
+                                             httpUrl("source.txt"),
+                                             { launcherPath: launcherPath,
+                                               launchWhenSucceeded: true });
+      yield promiseDownloadStopped(download);
+    }
+
+    let result = yield promiseFileLaunched;
+
+    // Verify that the results match the test case.
+    if (!launcherPath) {
+      // This indicates that the default handler has been chosen.
+      do_check_true(result === null);
+    } else {
+      // Check the nsIMIMEInfo instance that would have been used for launching.
+      do_check_eq(result.preferredAction, Ci.nsIMIMEInfo.useHelperApp);
+      do_check_true(result.preferredApplicationHandler
+                          .QueryInterface(Ci.nsILocalHandlerApp)
+                          .executable.equals(customLauncher));
+    }
+  }
+});
+
+/**
+ * Tests that the proper content type is set for a normal download.
+ */
+add_task(function* test_contentType() {
+  let download = yield promiseStartDownload(httpUrl("source.txt"));
+  yield promiseDownloadStopped(download);
+
+  do_check_eq("text/plain", download.contentType);
+});
+
+/**
+ * Tests that the serialization/deserialization of the startTime Date
+ * object works correctly.
+ */
+add_task(function* test_toSerializable_startTime()
+{
+  let download1 = yield promiseStartDownload(httpUrl("source.txt"));
+  yield promiseDownloadStopped(download1);
+
+  let serializable = download1.toSerializable();
+  let reserialized = JSON.parse(JSON.stringify(serializable));
+
+  let download2 = yield Downloads.createDownload(reserialized);
+
+  do_check_eq(download1.startTime.constructor.name, "Date");
+  do_check_eq(download2.startTime.constructor.name, "Date");
+  do_check_eq(download1.startTime.toJSON(), download2.startTime.toJSON());
+});
+
+/**
+ * Checks that downloads are added to browsing history when they start.
+ */
+add_task(function* test_history()
+{
+  mustInterruptResponses();
+
+  // We will wait for the visit to be notified during the download.
+  yield PlacesTestUtils.clearHistory();
+  let promiseVisit = promiseWaitForVisit(httpUrl("interruptible.txt"));
+
+  // Start a download that is not allowed to finish yet.
+  let download = yield promiseStartDownload(httpUrl("interruptible.txt"));
+
+  // The history notifications should be received before the download completes.
+  let [time, transitionType] = yield promiseVisit;
+  do_check_eq(time, download.startTime.getTime() * 1000);
+  do_check_eq(transitionType, Ci.nsINavHistoryService.TRANSITION_DOWNLOAD);
+
+  // Restart and complete the download after clearing history.
+  yield PlacesTestUtils.clearHistory();
+  download.cancel();
+  continueResponses();
+  yield download.start();
+
+  // The restart should not have added a new history visit.
+  do_check_false(yield promiseIsURIVisited(httpUrl("interruptible.txt")));
+});
+
+/**
+ * Checks that downloads started by nsIHelperAppService are added to the
+ * browsing history when they start.
+ */
+add_task(function* test_history_tryToKeepPartialData()
+{
+  // We will wait for the visit to be notified during the download.
+  yield PlacesTestUtils.clearHistory();
+  let promiseVisit =
+      promiseWaitForVisit(httpUrl("interruptible_resumable.txt"));
+
+  // Start a download that is not allowed to finish yet.
+  let beforeStartTimeMs = Date.now();
+  let download = yield promiseStartDownload_tryToKeepPartialData();
+
+  // The history notifications should be received before the download completes.
+  let [time, transitionType] = yield promiseVisit;
+  do_check_eq(transitionType, Ci.nsINavHistoryService.TRANSITION_DOWNLOAD);
+
+  // The time set by nsIHelperAppService may be different than the start time in
+  // the download object, thus we only check that it is a meaningful time.  Note
+  // that we subtract one second from the earliest time to account for rounding.
+  do_check_true(time >= beforeStartTimeMs * 1000 - 1000000);
+
+  // Complete the download before finishing the test.
+  continueResponses();
+  yield promiseDownloadStopped(download);
+});
+
+/**
+ * Tests that the temp download files are removed on exit and exiting private
+ * mode after they have been launched.
+ */
+add_task(function* test_launchWhenSucceeded_deleteTempFileOnExit() {
+  let customLauncherPath = getTempFile("app-launcher").path;
+  let autoDeleteTargetPathOne = getTempFile(TEST_TARGET_FILE_NAME).path;
+  let autoDeleteTargetPathTwo = getTempFile(TEST_TARGET_FILE_NAME).path;
+  let noAutoDeleteTargetPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+
+  let autoDeleteDownloadOne = yield Downloads.createDownload({
+    source: { url: httpUrl("source.txt"), isPrivate: true },
+    target: autoDeleteTargetPathOne,
+    launchWhenSucceeded: true,
+    launcherPath: customLauncherPath,
+  });
+  yield autoDeleteDownloadOne.start();
+
+  Services.prefs.setBoolPref(kDeleteTempFileOnExit, true);
+  let autoDeleteDownloadTwo = yield Downloads.createDownload({
+    source: httpUrl("source.txt"),
+    target: autoDeleteTargetPathTwo,
+    launchWhenSucceeded: true,
+    launcherPath: customLauncherPath,
+  });
+  yield autoDeleteDownloadTwo.start();
+
+  Services.prefs.setBoolPref(kDeleteTempFileOnExit, false);
+  let noAutoDeleteDownload = yield Downloads.createDownload({
+    source: httpUrl("source.txt"),
+    target: noAutoDeleteTargetPath,
+    launchWhenSucceeded: true,
+    launcherPath: customLauncherPath,
+  });
+  yield noAutoDeleteDownload.start();
+
+  Services.prefs.clearUserPref(kDeleteTempFileOnExit);
+
+  do_check_true(yield OS.File.exists(autoDeleteTargetPathOne));
+  do_check_true(yield OS.File.exists(autoDeleteTargetPathTwo));
+  do_check_true(yield OS.File.exists(noAutoDeleteTargetPath));
+
+  // Simulate leaving private browsing mode
+  Services.obs.notifyObservers(null, "last-pb-context-exited", null);
+  do_check_false(yield OS.File.exists(autoDeleteTargetPathOne));
+
+  // Simulate browser shutdown
+  let expire = Cc["@mozilla.org/uriloader/external-helper-app-service;1"]
+                 .getService(Ci.nsIObserver);
+  expire.observe(null, "profile-before-change", null);
+  do_check_false(yield OS.File.exists(autoDeleteTargetPathTwo));
+  do_check_true(yield OS.File.exists(noAutoDeleteTargetPath));
+});
diff --git a/toolkit/components/jsdownloads/test/unit/head.js b/toolkit/components/jsdownloads/test/unit/head.js
new file mode 100644
index 000000000..f322244c4
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/head.js
@@ -0,0 +1,843 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Provides infrastructure for automated download components tests.
+ */
+
+"use strict";
+
+// Globals
+
+var Cc = Components.classes;
+var Ci = Components.interfaces;
+var Cu = Components.utils;
+var Cr = Components.results;
+
+Cu.import("resource://gre/modules/Integration.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "DownloadPaths",
+                                  "resource://gre/modules/DownloadPaths.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Downloads",
+                                  "resource://gre/modules/Downloads.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
+                                  "resource://gre/modules/FileUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "HttpServer",
+                                  "resource://testing-common/httpd.js");
+XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
+                                  "resource://gre/modules/NetUtil.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PlacesTestUtils",
+                                  "resource://testing-common/PlacesTestUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils",
+                                  "resource://gre/modules/PlacesUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Promise",
+                                  "resource://gre/modules/Promise.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Services",
+                                  "resource://gre/modules/Services.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+                                  "resource://gre/modules/Task.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "OS",
+                                  "resource://gre/modules/osfile.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "MockRegistrar",
+                                  "resource://testing-common/MockRegistrar.jsm");
+
+XPCOMUtils.defineLazyServiceGetter(this, "gExternalHelperAppService",
+           "@mozilla.org/uriloader/external-helper-app-service;1",
+           Ci.nsIExternalHelperAppService);
+
+Integration.downloads.defineModuleGetter(this, "DownloadIntegration",
+            "resource://gre/modules/DownloadIntegration.jsm");
+
+const ServerSocket = Components.Constructor(
+                                "@mozilla.org/network/server-socket;1",
+                                "nsIServerSocket",
+                                "init");
+const BinaryOutputStream = Components.Constructor(
+                                      "@mozilla.org/binaryoutputstream;1",
+                                      "nsIBinaryOutputStream",
+                                      "setOutputStream")
+
+XPCOMUtils.defineLazyServiceGetter(this, "gMIMEService",
+                                   "@mozilla.org/mime;1",
+                                   "nsIMIMEService");
+
+const TEST_TARGET_FILE_NAME = "test-download.txt";
+const TEST_STORE_FILE_NAME = "test-downloads.json";
+
+const TEST_REFERRER_URL = "http://www.example.com/referrer.html";
+
+const TEST_DATA_SHORT = "This test string is downloaded.";
+// Generate using gzipCompressString in TelemetryController.jsm.
+const TEST_DATA_SHORT_GZIP_ENCODED_FIRST = [
+ 31, 139, 8, 0, 0, 0, 0, 0, 0, 3, 11, 201, 200, 44, 86, 40, 73, 45, 46, 81, 40, 46, 41, 202, 204
+];
+const TEST_DATA_SHORT_GZIP_ENCODED_SECOND = [
+  75, 87, 0, 114, 83, 242, 203, 243, 114, 242, 19, 83, 82, 83, 244, 0, 151, 222, 109, 43, 31, 0, 0, 0
+];
+const TEST_DATA_SHORT_GZIP_ENCODED =
+  TEST_DATA_SHORT_GZIP_ENCODED_FIRST.concat(TEST_DATA_SHORT_GZIP_ENCODED_SECOND);
+
+/**
+ * All the tests are implemented with add_task, this starts them automatically.
+ */
+function run_test()
+{
+  do_get_profile();
+  run_next_test();
+}
+
+// Support functions
+
+/**
+ * HttpServer object initialized before tests start.
+ */
+var gHttpServer;
+
+/**
+ * Given a file name, returns a string containing an URI that points to the file
+ * on the currently running instance of the test HTTP server.
+ */
+function httpUrl(aFileName) {
+  return "http://localhost:" + gHttpServer.identity.primaryPort + "/" +
+         aFileName;
+}
+
+// While the previous test file should have deleted all the temporary files it
+// used, on Windows these might still be pending deletion on the physical file
+// system.  Thus, start from a new base number every time, to make a collision
+// with a file that is still pending deletion highly unlikely.
+var gFileCounter = Math.floor(Math.random() * 1000000);
+
+/**
+ * Returns a reference to a temporary file, that is guaranteed not to exist, and
+ * to have never been created before.
+ *
+ * @param aLeafName
+ *        Suggested leaf name for the file to be created.
+ *
+ * @return nsIFile pointing to a non-existent file in a temporary directory.
+ *
+ * @note It is not enough to delete the file if it exists, or to delete the file
+ *       after calling nsIFile.createUnique, because on Windows the delete
+ *       operation in the file system may still be pending, preventing a new
+ *       file with the same name to be created.
+ */
+function getTempFile(aLeafName)
+{
+  // Prepend a serial number to the extension in the suggested leaf name.
+  let [base, ext] = DownloadPaths.splitBaseNameAndExtension(aLeafName);
+  let leafName = base + "-" + gFileCounter + ext;
+  gFileCounter++;
+
+  // Get a file reference under the temporary directory for this test file.
+  let file = FileUtils.getFile("TmpD", [leafName]);
+  do_check_false(file.exists());
+
+  do_register_cleanup(function () {
+    try {
+      file.remove(false)
+    } catch (e) {
+      if (!(e instanceof Components.Exception &&
+            (e.result == Cr.NS_ERROR_FILE_ACCESS_DENIED ||
+             e.result == Cr.NS_ERROR_FILE_TARGET_DOES_NOT_EXIST ||
+             e.result == Cr.NS_ERROR_FILE_NOT_FOUND))) {
+        throw e;
+      }
+      // On Windows, we may get an access denied error if the file existed before,
+      // and was recently deleted.
+      // Don't bother checking file.exists() as that may also cause an access
+      // denied error.
+    }
+  });
+
+  return file;
+}
+
+/**
+ * Waits for pending events to be processed.
+ *
+ * @return {Promise}
+ * @resolves When pending events have been processed.
+ * @rejects Never.
+ */
+function promiseExecuteSoon()
+{
+  let deferred = Promise.defer();
+  do_execute_soon(deferred.resolve);
+  return deferred.promise;
+}
+
+/**
+ * Waits for a pending events to be processed after a timeout.
+ *
+ * @return {Promise}
+ * @resolves When pending events have been processed.
+ * @rejects Never.
+ */
+function promiseTimeout(aTime)
+{
+  let deferred = Promise.defer();
+  do_timeout(aTime, deferred.resolve);
+  return deferred.promise;
+}
+
+/**
+ * Waits for a new history visit to be notified for the specified URI.
+ *
+ * @param aUrl
+ *        String containing the URI that will be visited.
+ *
+ * @return {Promise}
+ * @resolves Array [aTime, aTransitionType] from nsINavHistoryObserver.onVisit.
+ * @rejects Never.
+ */
+function promiseWaitForVisit(aUrl)
+{
+  let deferred = Promise.defer();
+
+  let uri = NetUtil.newURI(aUrl);
+
+  PlacesUtils.history.addObserver({
+    QueryInterface: XPCOMUtils.generateQI([Ci.nsINavHistoryObserver]),
+    onBeginUpdateBatch: function () {},
+    onEndUpdateBatch: function () {},
+    onVisit: function (aURI, aVisitID, aTime, aSessionID, aReferringID,
+                       aTransitionType, aGUID, aHidden) {
+      if (aURI.equals(uri)) {
+        PlacesUtils.history.removeObserver(this);
+        deferred.resolve([aTime, aTransitionType]);
+      }
+    },
+    onTitleChanged: function () {},
+    onDeleteURI: function () {},
+    onClearHistory: function () {},
+    onPageChanged: function () {},
+    onDeleteVisits: function () {},
+  }, false);
+
+  return deferred.promise;
+}
+
+/**
+ * Check browsing history to see whether the given URI has been visited.
+ *
+ * @param aUrl
+ *        String containing the URI that will be visited.
+ *
+ * @return {Promise}
+ * @resolves Boolean indicating whether the URI has been visited.
+ * @rejects JavaScript exception.
+ */
+function promiseIsURIVisited(aUrl) {
+  let deferred = Promise.defer();
+
+  PlacesUtils.asyncHistory.isURIVisited(NetUtil.newURI(aUrl),
+    function (aURI, aIsVisited) {
+      deferred.resolve(aIsVisited);
+    });
+
+  return deferred.promise;
+}
+
+/**
+ * Creates a new Download object, setting a temporary file as the target.
+ *
+ * @param aSourceUrl
+ *        String containing the URI for the download source, or null to use
+ *        httpUrl("source.txt").
+ *
+ * @return {Promise}
+ * @resolves The newly created Download object.
+ * @rejects JavaScript exception.
+ */
+function promiseNewDownload(aSourceUrl) {
+  return Downloads.createDownload({
+    source: aSourceUrl || httpUrl("source.txt"),
+    target: getTempFile(TEST_TARGET_FILE_NAME),
+  });
+}
+
+/**
+ * Starts a new download using the nsIWebBrowserPersist interface, and controls
+ * it using the legacy nsITransfer interface.
+ *
+ * @param aSourceUrl
+ *        String containing the URI for the download source, or null to use
+ *        httpUrl("source.txt").
+ * @param aOptions
+ *        An optional object used to control the behavior of this function.
+ *        You may pass an object with a subset of the following fields:
+ *        {
+ *          isPrivate: Boolean indicating whether the download originated from a
+ *                     private window.
+ *          targetFile: nsIFile for the target, or null to use a temporary file.
+ *          outPersist: Receives a reference to the created nsIWebBrowserPersist
+ *                      instance.
+ *          launchWhenSucceeded: Boolean indicating whether the target should
+ *                               be launched when it has completed successfully.
+ *          launcherPath: String containing the path of the custom executable to
+ *                        use to launch the target of the download.
+ *        }
+ *
+ * @return {Promise}
+ * @resolves The Download object created as a consequence of controlling the
+ *           download through the legacy nsITransfer interface.
+ * @rejects Never.  The current test fails in case of exceptions.
+ */
+function promiseStartLegacyDownload(aSourceUrl, aOptions) {
+  let sourceURI = NetUtil.newURI(aSourceUrl || httpUrl("source.txt"));
+  let targetFile = (aOptions && aOptions.targetFile)
+                   || getTempFile(TEST_TARGET_FILE_NAME);
+
+  let persist = Cc["@mozilla.org/embedding/browser/nsWebBrowserPersist;1"]
+                  .createInstance(Ci.nsIWebBrowserPersist);
+  if (aOptions) {
+    aOptions.outPersist = persist;
+  }
+
+  let fileExtension = null, mimeInfo = null;
+  let match = sourceURI.path.match(/\.([^.\/]+)$/);
+  if (match) {
+    fileExtension = match[1];
+  }
+
+  if (fileExtension) {
+    try {
+      mimeInfo = gMIMEService.getFromTypeAndExtension(null, fileExtension);
+      mimeInfo.preferredAction = Ci.nsIMIMEInfo.saveToDisk;
+    } catch (ex) { }
+  }
+
+  if (aOptions && aOptions.launcherPath) {
+    do_check_true(mimeInfo != null);
+
+    let localHandlerApp = Cc["@mozilla.org/uriloader/local-handler-app;1"]
+                            .createInstance(Ci.nsILocalHandlerApp);
+    localHandlerApp.executable = new FileUtils.File(aOptions.launcherPath);
+
+    mimeInfo.preferredApplicationHandler = localHandlerApp;
+    mimeInfo.preferredAction = Ci.nsIMIMEInfo.useHelperApp;
+  }
+
+  if (aOptions && aOptions.launchWhenSucceeded) {
+    do_check_true(mimeInfo != null);
+
+    mimeInfo.preferredAction = Ci.nsIMIMEInfo.useHelperApp;
+  }
+
+  // Apply decoding if required by the "Content-Encoding" header.
+  persist.persistFlags &= ~Ci.nsIWebBrowserPersist.PERSIST_FLAGS_NO_CONVERSION;
+  persist.persistFlags |=
+    Ci.nsIWebBrowserPersist.PERSIST_FLAGS_AUTODETECT_APPLY_CONVERSION;
+
+  let transfer = Cc["@mozilla.org/transfer;1"].createInstance(Ci.nsITransfer);
+
+  let deferred = Promise.defer();
+
+  Downloads.getList(Downloads.ALL).then(function (aList) {
+    // Temporarily register a view that will get notified when the download we
+    // are controlling becomes visible in the list of downloads.
+    aList.addView({
+      onDownloadAdded: function (aDownload) {
+        aList.removeView(this).then(null, do_report_unexpected_exception);
+
+        // Remove the download to keep the list empty for the next test.  This
+        // also allows the caller to register the "onchange" event directly.
+        let promise = aList.remove(aDownload);
+
+        // When the download object is ready, make it available to the caller.
+        promise.then(() => deferred.resolve(aDownload),
+                     do_report_unexpected_exception);
+      },
+    }).then(null, do_report_unexpected_exception);
+
+    let isPrivate = aOptions && aOptions.isPrivate;
+
+    // Initialize the components so they reference each other.  This will cause
+    // the Download object to be created and added to the public downloads.
+    transfer.init(sourceURI, NetUtil.newURI(targetFile), null, mimeInfo, null,
+                  null, persist, isPrivate);
+    persist.progressListener = transfer;
+
+    // Start the actual download process.
+    persist.savePrivacyAwareURI(sourceURI, null, null, 0, null, null, targetFile,
+                                isPrivate);
+  }.bind(this)).then(null, do_report_unexpected_exception);
+
+  return deferred.promise;
+}
+
+/**
+ * Starts a new download using the nsIHelperAppService interface, and controls
+ * it using the legacy nsITransfer interface.  The source of the download will
+ * be "interruptible_resumable.txt" and partially downloaded data will be kept.
+ *
+ * @param aSourceUrl
+ *        String containing the URI for the download source, or null to use
+ *        httpUrl("interruptible_resumable.txt").
+ *
+ * @return {Promise}
+ * @resolves The Download object created as a consequence of controlling the
+ *           download through the legacy nsITransfer interface.
+ * @rejects Never.  The current test fails in case of exceptions.
+ */
+function promiseStartExternalHelperAppServiceDownload(aSourceUrl) {
+  let sourceURI = NetUtil.newURI(aSourceUrl ||
+                                 httpUrl("interruptible_resumable.txt"));
+
+  let deferred = Promise.defer();
+
+  Downloads.getList(Downloads.PUBLIC).then(function (aList) {
+    // Temporarily register a view that will get notified when the download we
+    // are controlling becomes visible in the list of downloads.
+    aList.addView({
+      onDownloadAdded: function (aDownload) {
+        aList.removeView(this).then(null, do_report_unexpected_exception);
+
+        // Remove the download to keep the list empty for the next test.  This
+        // also allows the caller to register the "onchange" event directly.
+        let promise = aList.remove(aDownload);
+
+        // When the download object is ready, make it available to the caller.
+        promise.then(() => deferred.resolve(aDownload),
+                     do_report_unexpected_exception);
+      },
+    }).then(null, do_report_unexpected_exception);
+
+    let channel = NetUtil.newChannel({
+      uri: sourceURI,
+      loadUsingSystemPrincipal: true
+    });
+
+    // Start the actual download process.
+    channel.asyncOpen2({
+      contentListener: null,
+
+      onStartRequest: function (aRequest, aContext)
+      {
+        let requestChannel = aRequest.QueryInterface(Ci.nsIChannel);
+        this.contentListener = gExternalHelperAppService.doContent(
+                                     requestChannel.contentType, aRequest, null, true);
+        this.contentListener.onStartRequest(aRequest, aContext);
+      },
+
+      onStopRequest: function (aRequest, aContext, aStatusCode)
+      {
+        this.contentListener.onStopRequest(aRequest, aContext, aStatusCode);
+      },
+
+      onDataAvailable: function (aRequest, aContext, aInputStream, aOffset,
+                                 aCount)
+      {
+        this.contentListener.onDataAvailable(aRequest, aContext, aInputStream,
+                                             aOffset, aCount);
+      },
+    });
+  }.bind(this)).then(null, do_report_unexpected_exception);
+
+  return deferred.promise;
+}
+
+/**
+ * Waits for a download to reach half of its progress, in case it has not
+ * reached the expected progress already.
+ *
+ * @param aDownload
+ *        The Download object to wait upon.
+ *
+ * @return {Promise}
+ * @resolves When the download has reached half of its progress.
+ * @rejects Never.
+ */
+function promiseDownloadMidway(aDownload) {
+  let deferred = Promise.defer();
+
+  // Wait for the download to reach half of its progress.
+  let onchange = function () {
+    if (!aDownload.stopped && !aDownload.canceled && aDownload.progress == 50) {
+      aDownload.onchange = null;
+      deferred.resolve();
+    }
+  };
+
+  // Register for the notification, but also call the function directly in
+  // case the download already reached the expected progress.
+  aDownload.onchange = onchange;
+  onchange();
+
+  return deferred.promise;
+}
+
+/**
+ * Waits for a download to finish, in case it has not finished already.
+ *
+ * @param aDownload
+ *        The Download object to wait upon.
+ *
+ * @return {Promise}
+ * @resolves When the download has finished successfully.
+ * @rejects JavaScript exception if the download failed.
+ */
+function promiseDownloadStopped(aDownload) {
+  if (!aDownload.stopped) {
+    // The download is in progress, wait for the current attempt to finish and
+    // report any errors that may occur.
+    return aDownload.start();
+  }
+
+  if (aDownload.succeeded) {
+    return Promise.resolve();
+  }
+
+  // The download failed or was canceled.
+  return Promise.reject(aDownload.error || new Error("Download canceled."));
+}
+
+/**
+ * Returns a new public or private DownloadList object.
+ *
+ * @param aIsPrivate
+ *        True for the private list, false or undefined for the public list.
+ *
+ * @return {Promise}
+ * @resolves The newly created DownloadList object.
+ * @rejects JavaScript exception.
+ */
+function promiseNewList(aIsPrivate)
+{
+  // We need to clear all the internal state for the list and summary objects,
+  // since all the objects are interdependent internally.
+  Downloads._promiseListsInitialized = null;
+  Downloads._lists = {};
+  Downloads._summaries = {};
+
+  return Downloads.getList(aIsPrivate ? Downloads.PRIVATE : Downloads.PUBLIC);
+}
+
+/**
+ * Ensures that the given file contents are equal to the given string.
+ *
+ * @param aPath
+ *        String containing the path of the file whose contents should be
+ *        verified.
+ * @param aExpectedContents
+ *        String containing the octets that are expected in the file.
+ *
+ * @return {Promise}
+ * @resolves When the operation completes.
+ * @rejects Never.
+ */
+function promiseVerifyContents(aPath, aExpectedContents)
+{
+  return Task.spawn(function* () {
+    let file = new FileUtils.File(aPath);
+
+    if (!(yield OS.File.exists(aPath))) {
+      do_throw("File does not exist: " + aPath);
+    }
+
+    if ((yield OS.File.stat(aPath)).size == 0) {
+      do_throw("File is empty: " + aPath);
+    }
+
+    let deferred = Promise.defer();
+    NetUtil.asyncFetch(
+      { uri: NetUtil.newURI(file), loadUsingSystemPrincipal: true },
+      function(aInputStream, aStatus) {
+        do_check_true(Components.isSuccessCode(aStatus));
+        let contents = NetUtil.readInputStreamToString(aInputStream,
+                                                       aInputStream.available());
+        if (contents.length > TEST_DATA_SHORT.length * 2 ||
+            /[^\x20-\x7E]/.test(contents)) {
+          // Do not print the entire content string to the test log.
+          do_check_eq(contents.length, aExpectedContents.length);
+          do_check_true(contents == aExpectedContents);
+        } else {
+          // Print the string if it is short and made of printable characters.
+          do_check_eq(contents, aExpectedContents);
+        }
+        deferred.resolve();
+      });
+
+    yield deferred.promise;
+  });
+}
+
+/**
+ * Starts a socket listener that closes each incoming connection.
+ *
+ * @returns nsIServerSocket that listens for connections.  Call its "close"
+ *          method to stop listening and free the server port.
+ */
+function startFakeServer()
+{
+  let serverSocket = new ServerSocket(-1, true, -1);
+  serverSocket.asyncListen({
+    onSocketAccepted: function (aServ, aTransport) {
+      aTransport.close(Cr.NS_BINDING_ABORTED);
+    },
+    onStopListening: function () { },
+  });
+  return serverSocket;
+}
+
+/**
+ * This is an internal reference that should not be used directly by tests.
+ */
+var _gDeferResponses = Promise.defer();
+
+/**
+ * Ensures that all the interruptible requests started after this function is
+ * called won't complete until the continueResponses function is called.
+ *
+ * Normally, the internal HTTP server returns all the available data as soon as
+ * a request is received.  In order for some requests to be served one part at a
+ * time, special interruptible handlers are registered on the HTTP server.  This
+ * allows testing events or actions that need to happen in the middle of a
+ * download.
+ *
+ * For example, the handler accessible at the httpUri("interruptible.txt")
+ * address returns the TEST_DATA_SHORT text, then it may block until the
+ * continueResponses method is called.  At this point, the handler sends the
+ * TEST_DATA_SHORT text again to complete the response.
+ *
+ * If an interruptible request is started before the function is called, it may
+ * or may not be blocked depending on the actual sequence of events.
+ */
+function mustInterruptResponses()
+{
+  // If there are pending blocked requests, allow them to complete.  This is
+  // done to prevent requests from being blocked forever, but should not affect
+  // the test logic, since previously started requests should not be monitored
+  // on the client side anymore.
+  _gDeferResponses.resolve();
+
+  do_print("Interruptible responses will be blocked midway.");
+  _gDeferResponses = Promise.defer();
+}
+
+/**
+ * Allows all the current and future interruptible requests to complete.
+ */
+function continueResponses()
+{
+  do_print("Interruptible responses are now allowed to continue.");
+  _gDeferResponses.resolve();
+}
+
+/**
+ * Registers an interruptible response handler.
+ *
+ * @param aPath
+ *        Path passed to nsIHttpServer.registerPathHandler.
+ * @param aFirstPartFn
+ *        This function is called when the response is received, with the
+ *        aRequest and aResponse arguments of the server.
+ * @param aSecondPartFn
+ *        This function is called with the aRequest and aResponse arguments of
+ *        the server, when the continueResponses function is called.
+ */
+function registerInterruptibleHandler(aPath, aFirstPartFn, aSecondPartFn)
+{
+  gHttpServer.registerPathHandler(aPath, function (aRequest, aResponse) {
+    do_print("Interruptible request started.");
+
+    // Process the first part of the response.
+    aResponse.processAsync();
+    aFirstPartFn(aRequest, aResponse);
+
+    // Wait on the current deferred object, then finish the request.
+    _gDeferResponses.promise.then(function RIH_onSuccess() {
+      aSecondPartFn(aRequest, aResponse);
+      aResponse.finish();
+      do_print("Interruptible request finished.");
+    }).then(null, Cu.reportError);
+  });
+}
+
+/**
+ * Ensure the given date object is valid.
+ *
+ * @param aDate
+ *        The date object to be checked. This value can be null.
+ */
+function isValidDate(aDate) {
+  return aDate && aDate.getTime && !isNaN(aDate.getTime());
+}
+
+/**
+ * Position of the first byte served by the "interruptible_resumable.txt"
+ * handler during the most recent response.
+ */
+var gMostRecentFirstBytePos;
+
+// Initialization functions common to all tests
+
+add_task(function test_common_initialize()
+{
+  // Start the HTTP server.
+  gHttpServer = new HttpServer();
+  gHttpServer.registerDirectory("/", do_get_file("../data"));
+  gHttpServer.start(-1);
+  do_register_cleanup(() => {
+    return new Promise(resolve => {
+      // Ensure all the pending HTTP requests have a chance to finish.
+      continueResponses();
+      // Stop the HTTP server, calling resolve when it's done.
+      gHttpServer.stop(resolve);
+    });
+  });
+
+  // Cache locks might prevent concurrent requests to the same resource, and
+  // this may block tests that use the interruptible handlers.
+  Services.prefs.setBoolPref("browser.cache.disk.enable", false);
+  Services.prefs.setBoolPref("browser.cache.memory.enable", false);
+  do_register_cleanup(function () {
+    Services.prefs.clearUserPref("browser.cache.disk.enable");
+    Services.prefs.clearUserPref("browser.cache.memory.enable");
+  });
+
+  registerInterruptibleHandler("/interruptible.txt",
+    function firstPart(aRequest, aResponse) {
+      aResponse.setHeader("Content-Type", "text/plain", false);
+      aResponse.setHeader("Content-Length", "" + (TEST_DATA_SHORT.length * 2),
+                          false);
+      aResponse.write(TEST_DATA_SHORT);
+    }, function secondPart(aRequest, aResponse) {
+      aResponse.write(TEST_DATA_SHORT);
+    });
+
+  registerInterruptibleHandler("/interruptible_resumable.txt",
+    function firstPart(aRequest, aResponse) {
+      aResponse.setHeader("Content-Type", "text/plain", false);
+
+      // Determine if only part of the data should be sent.
+      let data = TEST_DATA_SHORT + TEST_DATA_SHORT;
+      if (aRequest.hasHeader("Range")) {
+        var matches = aRequest.getHeader("Range")
+                              .match(/^\s*bytes=(\d+)?-(\d+)?\s*$/);
+        var firstBytePos = (matches[1] === undefined) ? 0 : matches[1];
+        var lastBytePos = (matches[2] === undefined) ? data.length - 1
+                                            : matches[2];
+        if (firstBytePos >= data.length) {
+          aResponse.setStatusLine(aRequest.httpVersion, 416,
+                             "Requested Range Not Satisfiable");
+          aResponse.setHeader("Content-Range", "*/" + data.length, false);
+          aResponse.finish();
+          return;
+        }
+
+        aResponse.setStatusLine(aRequest.httpVersion, 206, "Partial Content");
+        aResponse.setHeader("Content-Range", firstBytePos + "-" +
+                                             lastBytePos + "/" +
+                                             data.length, false);
+
+        data = data.substring(firstBytePos, lastBytePos + 1);
+
+        gMostRecentFirstBytePos = firstBytePos;
+      } else {
+        gMostRecentFirstBytePos = 0;
+      }
+
+      aResponse.setHeader("Content-Length", "" + data.length, false);
+
+      aResponse.write(data.substring(0, data.length / 2));
+
+      // Store the second part of the data on the response object, so that it
+      // can be used by the secondPart function.
+      aResponse.secondPartData = data.substring(data.length / 2);
+    }, function secondPart(aRequest, aResponse) {
+      aResponse.write(aResponse.secondPartData);
+    });
+
+  registerInterruptibleHandler("/interruptible_gzip.txt",
+    function firstPart(aRequest, aResponse) {
+      aResponse.setHeader("Content-Type", "text/plain", false);
+      aResponse.setHeader("Content-Encoding", "gzip", false);
+      aResponse.setHeader("Content-Length", "" + TEST_DATA_SHORT_GZIP_ENCODED.length);
+
+      let bos =  new BinaryOutputStream(aResponse.bodyOutputStream);
+      bos.writeByteArray(TEST_DATA_SHORT_GZIP_ENCODED_FIRST,
+                         TEST_DATA_SHORT_GZIP_ENCODED_FIRST.length);
+    }, function secondPart(aRequest, aResponse) {
+      let bos =  new BinaryOutputStream(aResponse.bodyOutputStream);
+      bos.writeByteArray(TEST_DATA_SHORT_GZIP_ENCODED_SECOND,
+                         TEST_DATA_SHORT_GZIP_ENCODED_SECOND.length);
+    });
+
+  gHttpServer.registerPathHandler("/shorter-than-content-length-http-1-1.txt",
+    function (aRequest, aResponse) {
+      aResponse.processAsync();
+      aResponse.setStatusLine("1.1", 200, "OK");
+      aResponse.setHeader("Content-Type", "text/plain", false);
+      aResponse.setHeader("Content-Length", "" + (TEST_DATA_SHORT.length * 2),
+                          false);
+      aResponse.write(TEST_DATA_SHORT);
+      aResponse.finish();
+    });
+
+  // This URL will emulate being blocked by Windows Parental controls
+  gHttpServer.registerPathHandler("/parentalblocked.zip",
+    function (aRequest, aResponse) {
+      aResponse.setStatusLine(aRequest.httpVersion, 450,
+                              "Blocked by Windows Parental Controls");
+    });
+
+  // During unit tests, most of the functions that require profile access or
+  // operating system features will be disabled. Individual tests may override
+  // them again to check for specific behaviors.
+  Integration.downloads.register(base => ({
+    __proto__: base,
+    loadPublicDownloadListFromStore: () => Promise.resolve(),
+    shouldKeepBlockedData: () => Promise.resolve(false),
+    shouldBlockForParentalControls: () => Promise.resolve(false),
+    shouldBlockForRuntimePermissions: () => Promise.resolve(false),
+    shouldBlockForReputationCheck: () => Promise.resolve({
+      shouldBlock: false,
+      verdict: "",
+    }),
+    confirmLaunchExecutable: () => Promise.resolve(),
+    launchFile: () => Promise.resolve(),
+    showContainingDirectory: () => Promise.resolve(),
+    // This flag allows re-enabling the default observers during their tests.
+    allowObservers: false,
+    addListObservers() {
+      return this.allowObservers ? super.addListObservers(...arguments)
+                                 : Promise.resolve();
+    },
+    // This flag allows re-enabling the download directory logic for its tests.
+    _allowDirectories: false,
+    set allowDirectories(value) {
+      this._allowDirectories = value;
+      // We have to invalidate the previously computed directory path.
+      this._downloadsDirectory = null;
+    },
+    _getDirectory(name) {
+      return super._getDirectory(this._allowDirectories ? name : "TmpD");
+    },
+  }));
+
+  // Make sure that downloads started using nsIExternalHelperAppService are
+  // saved to disk without asking for a destination interactively.
+  let mock = {
+    QueryInterface: XPCOMUtils.generateQI([Ci.nsIHelperAppLauncherDialog]),
+    promptForSaveToFileAsync(aLauncher,
+                             aWindowContext,
+                             aDefaultFileName,
+                             aSuggestedFileExtension,
+                             aForcePrompt) {
+      // The dialog should create the empty placeholder file.
+      let file = getTempFile(TEST_TARGET_FILE_NAME);
+      file.create(Ci.nsIFile.NORMAL_FILE_TYPE, FileUtils.PERMS_FILE);
+      aLauncher.saveDestinationAvailable(file);
+    },
+  };
+
+  let cid = MockRegistrar.register("@mozilla.org/helperapplauncherdialog;1", mock);
+  do_register_cleanup(() => {
+    MockRegistrar.unregister(cid);
+  });
+});
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadCore.js b/toolkit/components/jsdownloads/test/unit/test_DownloadCore.js
new file mode 100644
index 000000000..6e32c63d3
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadCore.js
@@ -0,0 +1,87 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the main download interfaces using DownloadCopySaver.
+ */
+
+"use strict";
+
+XPCOMUtils.defineLazyModuleGetter(this, "DownloadError",
+                                  "resource://gre/modules/DownloadCore.jsm");
+
+// Execution of common tests
+
+var gUseLegacySaver = false;
+
+var scriptFile = do_get_file("common_test_Download.js");
+Services.scriptloader.loadSubScript(NetUtil.newURI(scriptFile).spec);
+
+// Tests
+
+/**
+ * Tests the DownloadError object.
+ */
+add_task(function test_DownloadError()
+{
+  let error = new DownloadError({ result: Cr.NS_ERROR_NOT_RESUMABLE,
+                                  message: "Not resumable."});
+  do_check_eq(error.result, Cr.NS_ERROR_NOT_RESUMABLE);
+  do_check_eq(error.message, "Not resumable.");
+  do_check_false(error.becauseSourceFailed);
+  do_check_false(error.becauseTargetFailed);
+  do_check_false(error.becauseBlocked);
+  do_check_false(error.becauseBlockedByParentalControls);
+
+  error = new DownloadError({ message: "Unknown error."});
+  do_check_eq(error.result, Cr.NS_ERROR_FAILURE);
+  do_check_eq(error.message, "Unknown error.");
+
+  error = new DownloadError({ result: Cr.NS_ERROR_NOT_RESUMABLE });
+  do_check_eq(error.result, Cr.NS_ERROR_NOT_RESUMABLE);
+  do_check_true(error.message.indexOf("Exception") > 0);
+
+  // becauseSourceFailed will be set, but not the unknown property.
+  error = new DownloadError({ message: "Unknown error.",
+                              becauseSourceFailed: true,
+                              becauseUnknown: true });
+  do_check_true(error.becauseSourceFailed);
+  do_check_false("becauseUnknown" in error);
+
+  error = new DownloadError({ result: Cr.NS_ERROR_MALFORMED_URI,
+                              inferCause: true });
+  do_check_eq(error.result, Cr.NS_ERROR_MALFORMED_URI);
+  do_check_true(error.becauseSourceFailed);
+  do_check_false(error.becauseTargetFailed);
+  do_check_false(error.becauseBlocked);
+  do_check_false(error.becauseBlockedByParentalControls);
+
+  // This test does not set inferCause, so becauseSourceFailed will not be set.
+  error = new DownloadError({ result: Cr.NS_ERROR_MALFORMED_URI });
+  do_check_eq(error.result, Cr.NS_ERROR_MALFORMED_URI);
+  do_check_false(error.becauseSourceFailed);
+
+  error = new DownloadError({ result: Cr.NS_ERROR_FILE_INVALID_PATH,
+                              inferCause: true });
+  do_check_eq(error.result, Cr.NS_ERROR_FILE_INVALID_PATH);
+  do_check_false(error.becauseSourceFailed);
+  do_check_true(error.becauseTargetFailed);
+  do_check_false(error.becauseBlocked);
+  do_check_false(error.becauseBlockedByParentalControls);
+
+  error = new DownloadError({ becauseBlocked: true });
+  do_check_eq(error.message, "Download blocked.");
+  do_check_false(error.becauseSourceFailed);
+  do_check_false(error.becauseTargetFailed);
+  do_check_true(error.becauseBlocked);
+  do_check_false(error.becauseBlockedByParentalControls);
+
+  error = new DownloadError({ becauseBlockedByParentalControls: true });
+  do_check_eq(error.message, "Download blocked.");
+  do_check_false(error.becauseSourceFailed);
+  do_check_false(error.becauseTargetFailed);
+  do_check_true(error.becauseBlocked);
+  do_check_true(error.becauseBlockedByParentalControls);
+});
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadImport.js b/toolkit/components/jsdownloads/test/unit/test_DownloadImport.js
new file mode 100644
index 000000000..388870f00
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadImport.js
@@ -0,0 +1,701 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the DownloadImport object.
+ */
+
+"use strict";
+
+// Globals
+
+XPCOMUtils.defineLazyModuleGetter(this, "Sqlite",
+                                  "resource://gre/modules/Sqlite.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "DownloadImport",
+                                  "resource://gre/modules/DownloadImport.jsm");
+
+// Importable states
+const DOWNLOAD_NOTSTARTED = -1;
+const DOWNLOAD_DOWNLOADING = 0;
+const DOWNLOAD_PAUSED = 4;
+const DOWNLOAD_QUEUED = 5;
+
+// Non importable states
+const DOWNLOAD_FAILED = 2;
+const DOWNLOAD_CANCELED = 3;
+const DOWNLOAD_BLOCKED_PARENTAL = 6;
+const DOWNLOAD_SCANNING = 7;
+const DOWNLOAD_DIRTY = 8;
+const DOWNLOAD_BLOCKED_POLICY = 9;
+
+// The TEST_DATA_TAINTED const is a version of TEST_DATA_SHORT in which the
+// beginning of the data was changed (with the TEST_DATA_REPLACEMENT value).
+// We use this to test that the entityID is properly imported and the download
+// can be resumed from where it was paused.
+// For simplification purposes, the test requires that TEST_DATA_SHORT and
+// TEST_DATA_TAINTED have the same length.
+const TEST_DATA_REPLACEMENT = "-changed- ";
+const TEST_DATA_TAINTED = TEST_DATA_REPLACEMENT +
+                          TEST_DATA_SHORT.substr(TEST_DATA_REPLACEMENT.length);
+const TEST_DATA_LENGTH = TEST_DATA_SHORT.length;
+
+// The length of the partial file that we'll write to disk as an existing
+// ongoing download.
+const TEST_DATA_PARTIAL_LENGTH = TEST_DATA_REPLACEMENT.length;
+
+// The value of the "maxBytes" column stored in the DB about the downloads.
+// It's intentionally different than TEST_DATA_LENGTH to test that each value
+// is seen when expected.
+const MAXBYTES_IN_DB = TEST_DATA_LENGTH - 10;
+
+var gDownloadsRowToImport;
+var gDownloadsRowNonImportable;
+
+/**
+ * Creates a database with an empty moz_downloads table and leaves an
+ * open connection to it.
+ *
+ * @param aPath
+ *        String containing the path of the database file to be created.
+ * @param aSchemaVersion
+ *        Number with the version of the database schema to set.
+ *
+ * @return {Promise}
+ * @resolves The open connection to the database.
+ * @rejects If an error occurred during the database creation.
+ */
+function promiseEmptyDatabaseConnection({aPath, aSchemaVersion}) {
+  return Task.spawn(function* () {
+    let connection = yield Sqlite.openConnection({ path: aPath });
+
+    yield connection.execute("CREATE TABLE moz_downloads ("
+                             + "id INTEGER PRIMARY KEY,"
+                             + "name TEXT,"
+                             + "source TEXT,"
+                             + "target TEXT,"
+                             + "tempPath TEXT,"
+                             + "startTime INTEGER,"
+                             + "endTime INTEGER,"
+                             + "state INTEGER,"
+                             + "referrer TEXT,"
+                             + "entityID TEXT,"
+                             + "currBytes INTEGER NOT NULL DEFAULT 0,"
+                             + "maxBytes INTEGER NOT NULL DEFAULT -1,"
+                             + "mimeType TEXT,"
+                             + "preferredApplication TEXT,"
+                             + "preferredAction INTEGER NOT NULL DEFAULT 0,"
+                             + "autoResume INTEGER NOT NULL DEFAULT 0,"
+                             + "guid TEXT)");
+
+    yield connection.setSchemaVersion(aSchemaVersion);
+
+    return connection;
+  });
+}
+
+/**
+ * Inserts a new entry in the database with the given columns' values.
+ *
+ * @param aConnection
+ *        The database connection.
+ * @param aDownloadRow
+ *        An object representing the values for each column of the row
+ *        being inserted.
+ *
+ * @return {Promise}
+ * @resolves When the operation completes.
+ * @rejects If there's an error inserting the row.
+ */
+function promiseInsertRow(aConnection, aDownloadRow) {
+  // We can't use the aDownloadRow obj directly in the execute statement
+  // because the obj bind code in Sqlite.jsm doesn't allow objects
+  // with extra properties beyond those being binded. So we might as well
+  // use an array as it is simpler.
+  let values = [
+    aDownloadRow.source, aDownloadRow.target, aDownloadRow.tempPath,
+    aDownloadRow.startTime.getTime() * 1000, aDownloadRow.state,
+    aDownloadRow.referrer, aDownloadRow.entityID, aDownloadRow.maxBytes,
+    aDownloadRow.mimeType, aDownloadRow.preferredApplication,
+    aDownloadRow.preferredAction, aDownloadRow.autoResume
+  ];
+
+  return aConnection.execute("INSERT INTO moz_downloads ("
+                            + "name, source, target, tempPath, startTime,"
+                            + "endTime, state, referrer, entityID, currBytes,"
+                            + "maxBytes, mimeType, preferredApplication,"
+                            + "preferredAction, autoResume, guid)"
+                            + "VALUES ("
+                            + "'', ?, ?, ?, ?, " // name,
+                            + "0, ?, ?, ?, 0, "  // endTime, currBytes
+                            + " ?, ?, ?, "       //
+                            + " ?, ?, '')",      // and guid are not imported
+                            values);
+}
+
+/**
+ * Retrieves the number of rows in the moz_downloads table of the
+ * database.
+ *
+ * @param aConnection
+ *        The database connection.
+ *
+ * @return {Promise}
+ * @resolves With the number of rows.
+ * @rejects Never.
+ */
+function promiseTableCount(aConnection) {
+  return aConnection.execute("SELECT COUNT(*) FROM moz_downloads")
+                    .then(res => res[0].getResultByName("COUNT(*)"))
+                    .then(null, Cu.reportError);
+}
+
+/**
+ * Briefly opens a network channel to a given URL to retrieve
+ * the entityID of this url, as generated by the network code.
+ *
+ * @param aUrl
+ *        The URL to retrieve the entityID.
+ *
+ * @return {Promise}
+ * @resolves The EntityID of the given URL.
+ * @rejects When there's a problem accessing the URL.
+ */
+function promiseEntityID(aUrl) {
+  let deferred = Promise.defer();
+  let entityID = "";
+  let channel = NetUtil.newChannel({
+    uri: NetUtil.newURI(aUrl),
+    loadUsingSystemPrincipal: true
+  });
+
+  channel.asyncOpen2({
+    onStartRequest: function (aRequest) {
+      if (aRequest instanceof Ci.nsIResumableChannel) {
+        entityID = aRequest.entityID;
+      }
+      aRequest.cancel(Cr.NS_BINDING_ABORTED);
+    },
+
+    onStopRequest: function (aRequest, aContext, aStatusCode) {
+      if (aStatusCode == Cr.NS_BINDING_ABORTED) {
+        deferred.resolve(entityID);
+      } else {
+        deferred.reject("Unexpected status code received");
+      }
+    },
+
+    onDataAvailable: function () {}
+  });
+
+  return deferred.promise;
+}
+
+/**
+ * Gets a file path to a temporary writeable download target, in the
+ * correct format as expected to be stored in the downloads database,
+ * which is file:///absolute/path/to/file
+ *
+ * @param aLeafName
+ *        A hint leaf name for the file.
+ *
+ * @return String The path to the download target.
+ */
+function getDownloadTarget(aLeafName) {
+  return NetUtil.newURI(getTempFile(aLeafName)).spec;
+}
+
+/**
+ * Generates a temporary partial file to use as an in-progress
+ * download. The file is written to disk with a part of the total expected
+ * download content pre-written.
+ *
+ * @param aLeafName
+ *        A hint leaf name for the file.
+ * @param aTainted
+ *        A boolean value. When true, the partial content of the file
+ *        will be different from the expected content of the original source
+ *        file. See the declaration of TEST_DATA_TAINTED for more information.
+ *
+ * @return {Promise}
+ * @resolves When the operation completes, and returns a string with the path
+ *           to the generated file.
+ * @rejects If there's an error writing the file.
+ */
+function getPartialFile(aLeafName, aTainted = false) {
+  let tempDownload = getTempFile(aLeafName);
+  let partialContent = aTainted
+                     ? TEST_DATA_TAINTED.substr(0, TEST_DATA_PARTIAL_LENGTH)
+                     : TEST_DATA_SHORT.substr(0, TEST_DATA_PARTIAL_LENGTH);
+
+  return OS.File.writeAtomic(tempDownload.path, partialContent,
+                             { tmpPath: tempDownload.path + ".tmp",
+                               flush: true })
+                .then(() => tempDownload.path);
+}
+
+/**
+ * Generates a Date object to be used as the startTime for the download rows
+ * in the DB. A date that is obviously different from the current time is
+ * generated to make sure this stored data and a `new Date()` can't collide.
+ *
+ * @param aOffset
+ *        A offset from the base generated date is used to differentiate each
+ *        row in the database.
+ *
+ * @return A Date object.
+ */
+function getStartTime(aOffset) {
+  return new Date(1000000 + (aOffset * 10000));
+}
+
+/**
+ * Performs various checks on an imported Download object to make sure
+ * all properties are properly set as expected from the import procedure.
+ *
+ * @param aDownload
+ *        The Download object to be checked.
+ * @param aDownloadRow
+ *        An object that represents a row from the original database table,
+ *        with extra properties describing expected values that are not
+ *        explictly part of the database.
+ *
+ * @return {Promise}
+ * @resolves When the operation completes
+ * @rejects Never
+ */
+function checkDownload(aDownload, aDownloadRow) {
+  return Task.spawn(function*() {
+    do_check_eq(aDownload.source.url, aDownloadRow.source);
+    do_check_eq(aDownload.source.referrer, aDownloadRow.referrer);
+
+    do_check_eq(aDownload.target.path,
+                NetUtil.newURI(aDownloadRow.target)
+                       .QueryInterface(Ci.nsIFileURL).file.path);
+
+    do_check_eq(aDownload.target.partFilePath, aDownloadRow.tempPath);
+
+    if (aDownloadRow.expectedResume) {
+      do_check_true(!aDownload.stopped || aDownload.succeeded);
+      yield promiseDownloadStopped(aDownload);
+
+      do_check_true(aDownload.succeeded);
+      do_check_eq(aDownload.progress, 100);
+      // If the download has resumed, a new startTime will be set.
+      // By calling toJSON we're also testing that startTime is a Date object.
+      do_check_neq(aDownload.startTime.toJSON(),
+                   aDownloadRow.startTime.toJSON());
+    } else {
+      do_check_false(aDownload.succeeded);
+      do_check_eq(aDownload.startTime.toJSON(),
+                  aDownloadRow.startTime.toJSON());
+    }
+
+    do_check_eq(aDownload.stopped, true);
+
+    let serializedSaver = aDownload.saver.toSerializable();
+    if (typeof(serializedSaver) == "object") {
+      do_check_eq(serializedSaver.type, "copy");
+    } else {
+      do_check_eq(serializedSaver, "copy");
+    }
+
+    if (aDownloadRow.entityID) {
+      do_check_eq(aDownload.saver.entityID, aDownloadRow.entityID);
+    }
+
+    do_check_eq(aDownload.currentBytes, aDownloadRow.expectedCurrentBytes);
+    do_check_eq(aDownload.totalBytes, aDownloadRow.expectedTotalBytes);
+
+    if (aDownloadRow.expectedContent) {
+      let fileToCheck = aDownloadRow.expectedResume
+                        ? aDownload.target.path
+                        : aDownload.target.partFilePath;
+      yield promiseVerifyContents(fileToCheck, aDownloadRow.expectedContent);
+    }
+
+    do_check_eq(aDownload.contentType, aDownloadRow.expectedContentType);
+    do_check_eq(aDownload.launcherPath, aDownloadRow.preferredApplication);
+
+    do_check_eq(aDownload.launchWhenSucceeded,
+                aDownloadRow.preferredAction != Ci.nsIMIMEInfo.saveToDisk);
+  });
+}
+
+// Preparation tasks
+
+/**
+ * Prepares the list of downloads to be added to the database that should
+ * be imported by the import procedure.
+ */
+add_task(function* prepareDownloadsToImport() {
+
+  let sourceUrl = httpUrl("source.txt");
+  let sourceEntityId = yield promiseEntityID(sourceUrl);
+
+  gDownloadsRowToImport = [
+    // Paused download with autoResume and a partial file. By
+    // setting the correct entityID the download can resume from
+    // where it stopped, and to test that this works properly we
+    // intentionally set different data in the beginning of the
+    // partial file to make sure it was not replaced.
+    {
+      source: sourceUrl,
+      target: getDownloadTarget("inprogress1.txt"),
+      tempPath: yield getPartialFile("inprogress1.txt.part", true),
+      startTime: getStartTime(1),
+      state: DOWNLOAD_PAUSED,
+      referrer: httpUrl("referrer1"),
+      entityID: sourceEntityId,
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType1",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication1",
+      autoResume: 1,
+
+      // Even though the information stored in the DB said
+      // maxBytes was MAXBYTES_IN_DB, the download turned out to be
+      // a different length. Here we make sure the totalBytes property
+      // was correctly set with the actual value. The same consideration
+      // applies to the contentType.
+      expectedCurrentBytes: TEST_DATA_LENGTH,
+      expectedTotalBytes: TEST_DATA_LENGTH,
+      expectedResume: true,
+      expectedContentType: "text/plain",
+      expectedContent: TEST_DATA_TAINTED,
+    },
+
+    // Paused download with autoResume and a partial file,
+    // but missing entityID. This means that the download will
+    // start from beginning, and the entire original content of the
+    // source file should replace the different data that was stored
+    // in the partial file.
+    {
+      source: sourceUrl,
+      target: getDownloadTarget("inprogress2.txt"),
+      tempPath: yield getPartialFile("inprogress2.txt.part", true),
+      startTime: getStartTime(2),
+      state: DOWNLOAD_PAUSED,
+      referrer: httpUrl("referrer2"),
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType2",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication2",
+      autoResume: 1,
+
+      expectedCurrentBytes: TEST_DATA_LENGTH,
+      expectedTotalBytes: TEST_DATA_LENGTH,
+      expectedResume: true,
+      expectedContentType: "text/plain",
+      expectedContent: TEST_DATA_SHORT
+    },
+
+    // Paused download with no autoResume and a partial file.
+    {
+      source: sourceUrl,
+      target: getDownloadTarget("inprogress3.txt"),
+      tempPath: yield getPartialFile("inprogress3.txt.part"),
+      startTime: getStartTime(3),
+      state: DOWNLOAD_PAUSED,
+      referrer: httpUrl("referrer3"),
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType3",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication3",
+      autoResume: 0,
+
+      // Since this download has not been resumed, the actual data
+      // about its total size and content type is not known.
+      // Therefore, we're going by the information imported from the DB.
+      expectedCurrentBytes: TEST_DATA_PARTIAL_LENGTH,
+      expectedTotalBytes: MAXBYTES_IN_DB,
+      expectedResume: false,
+      expectedContentType: "mimeType3",
+      expectedContent: TEST_DATA_SHORT.substr(0, TEST_DATA_PARTIAL_LENGTH),
+    },
+
+    // Paused download with autoResume and no partial file.
+    {
+      source: sourceUrl,
+      target: getDownloadTarget("inprogress4.txt"),
+      tempPath: "",
+      startTime: getStartTime(4),
+      state: DOWNLOAD_PAUSED,
+      referrer: httpUrl("referrer4"),
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "text/plain",
+      preferredAction: Ci.nsIMIMEInfo.useHelperApp,
+      preferredApplication: "prerredApplication4",
+      autoResume: 1,
+
+      expectedCurrentBytes: TEST_DATA_LENGTH,
+      expectedTotalBytes: TEST_DATA_LENGTH,
+      expectedResume: true,
+      expectedContentType: "text/plain",
+      expectedContent: TEST_DATA_SHORT
+    },
+
+    // Paused download with no autoResume and no partial file.
+    {
+      source: sourceUrl,
+      target: getDownloadTarget("inprogress5.txt"),
+      tempPath: "",
+      startTime: getStartTime(5),
+      state: DOWNLOAD_PAUSED,
+      referrer: httpUrl("referrer4"),
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "text/plain",
+      preferredAction: Ci.nsIMIMEInfo.useSystemDefault,
+      preferredApplication: "prerredApplication5",
+      autoResume: 0,
+
+      expectedCurrentBytes: 0,
+      expectedTotalBytes: MAXBYTES_IN_DB,
+      expectedResume: false,
+      expectedContentType: "text/plain",
+    },
+
+    // Queued download with no autoResume and no partial file.
+    // Even though autoResume=0, queued downloads always autoResume.
+    {
+      source: sourceUrl,
+      target: getDownloadTarget("inprogress6.txt"),
+      tempPath: "",
+      startTime: getStartTime(6),
+      state: DOWNLOAD_QUEUED,
+      referrer: httpUrl("referrer6"),
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "text/plain",
+      preferredAction: Ci.nsIMIMEInfo.useHelperApp,
+      preferredApplication: "prerredApplication6",
+      autoResume: 0,
+
+      expectedCurrentBytes: TEST_DATA_LENGTH,
+      expectedTotalBytes: TEST_DATA_LENGTH,
+      expectedResume: true,
+      expectedContentType: "text/plain",
+      expectedContent: TEST_DATA_SHORT
+    },
+
+    // Notstarted download with no autoResume and no partial file.
+    // Even though autoResume=0, notstarted downloads always autoResume.
+    {
+      source: sourceUrl,
+      target: getDownloadTarget("inprogress7.txt"),
+      tempPath: "",
+      startTime: getStartTime(7),
+      state: DOWNLOAD_NOTSTARTED,
+      referrer: httpUrl("referrer7"),
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "text/plain",
+      preferredAction: Ci.nsIMIMEInfo.useHelperApp,
+      preferredApplication: "prerredApplication7",
+      autoResume: 0,
+
+      expectedCurrentBytes: TEST_DATA_LENGTH,
+      expectedTotalBytes: TEST_DATA_LENGTH,
+      expectedResume: true,
+      expectedContentType: "text/plain",
+      expectedContent: TEST_DATA_SHORT
+    },
+
+    // Downloading download with no autoResume and a partial file.
+    // Even though autoResume=0, downloading downloads always autoResume.
+    {
+      source: sourceUrl,
+      target: getDownloadTarget("inprogress8.txt"),
+      tempPath: yield getPartialFile("inprogress8.txt.part", true),
+      startTime: getStartTime(8),
+      state: DOWNLOAD_DOWNLOADING,
+      referrer: httpUrl("referrer8"),
+      entityID: sourceEntityId,
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "text/plain",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication8",
+      autoResume: 0,
+
+      expectedCurrentBytes: TEST_DATA_LENGTH,
+      expectedTotalBytes: TEST_DATA_LENGTH,
+      expectedResume: true,
+      expectedContentType: "text/plain",
+      expectedContent: TEST_DATA_TAINTED
+    },
+  ];
+});
+
+/**
+ * Prepares the list of downloads to be added to the database that should
+ * *not* be imported by the import procedure.
+ */
+add_task(function* prepareNonImportableDownloads()
+{
+  gDownloadsRowNonImportable = [
+    // Download with no source (should never happen in normal circumstances).
+    {
+      source: "",
+      target: "nonimportable1.txt",
+      tempPath: "",
+      startTime: getStartTime(1),
+      state: DOWNLOAD_PAUSED,
+      referrer: "",
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType1",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication1",
+      autoResume: 1
+    },
+
+    // state = DOWNLOAD_FAILED
+    {
+      source: httpUrl("source.txt"),
+      target: "nonimportable2.txt",
+      tempPath: "",
+      startTime: getStartTime(2),
+      state: DOWNLOAD_FAILED,
+      referrer: "",
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType2",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication2",
+      autoResume: 1
+    },
+
+    // state = DOWNLOAD_CANCELED
+    {
+      source: httpUrl("source.txt"),
+      target: "nonimportable3.txt",
+      tempPath: "",
+      startTime: getStartTime(3),
+      state: DOWNLOAD_CANCELED,
+      referrer: "",
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType3",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication3",
+      autoResume: 1
+    },
+
+    // state = DOWNLOAD_BLOCKED_PARENTAL
+    {
+      source: httpUrl("source.txt"),
+      target: "nonimportable4.txt",
+      tempPath: "",
+      startTime: getStartTime(4),
+      state: DOWNLOAD_BLOCKED_PARENTAL,
+      referrer: "",
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType4",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication4",
+      autoResume: 1
+    },
+
+    // state = DOWNLOAD_SCANNING
+    {
+      source: httpUrl("source.txt"),
+      target: "nonimportable5.txt",
+      tempPath: "",
+      startTime: getStartTime(5),
+      state: DOWNLOAD_SCANNING,
+      referrer: "",
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType5",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication5",
+      autoResume: 1
+    },
+
+    // state = DOWNLOAD_DIRTY
+    {
+      source: httpUrl("source.txt"),
+      target: "nonimportable6.txt",
+      tempPath: "",
+      startTime: getStartTime(6),
+      state: DOWNLOAD_DIRTY,
+      referrer: "",
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType6",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication6",
+      autoResume: 1
+    },
+
+    // state = DOWNLOAD_BLOCKED_POLICY
+    {
+      source: httpUrl("source.txt"),
+      target: "nonimportable7.txt",
+      tempPath: "",
+      startTime: getStartTime(7),
+      state: DOWNLOAD_BLOCKED_POLICY,
+      referrer: "",
+      entityID: "",
+      maxBytes: MAXBYTES_IN_DB,
+      mimeType: "mimeType7",
+      preferredAction: Ci.nsIMIMEInfo.saveToDisk,
+      preferredApplication: "prerredApplication7",
+      autoResume: 1
+    },
+  ];
+});
+
+// Test
+
+/**
+ * Creates a temporary Sqlite database with download data and perform an
+ * import of that data to the new Downloads API to verify that the import
+ * worked correctly.
+ */
+add_task(function* test_downloadImport()
+{
+  let connection = null;
+  let downloadsSqlite = getTempFile("downloads.sqlite").path;
+
+  try {
+    // Set up the database.
+    connection = yield promiseEmptyDatabaseConnection({
+      aPath: downloadsSqlite,
+      aSchemaVersion: 9
+    });
+
+    // Insert both the importable and non-importable
+    // downloads together.
+    for (let downloadRow of gDownloadsRowToImport) {
+      yield promiseInsertRow(connection, downloadRow);
+    }
+
+    for (let downloadRow of gDownloadsRowNonImportable) {
+      yield promiseInsertRow(connection, downloadRow);
+    }
+
+    // Check that every item was inserted.
+    do_check_eq((yield promiseTableCount(connection)),
+                gDownloadsRowToImport.length +
+                gDownloadsRowNonImportable.length);
+  } finally {
+    // Close the connection so that DownloadImport can open it.
+    yield connection.close();
+  }
+
+  // Import items.
+  let list = yield promiseNewList(false);
+  yield new DownloadImport(list, downloadsSqlite).import();
+  let items = yield list.getAll();
+
+  do_check_eq(items.length, gDownloadsRowToImport.length);
+
+  for (let i = 0; i < gDownloadsRowToImport.length; i++) {
+    yield checkDownload(items[i], gDownloadsRowToImport[i]);
+  }
+})
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadIntegration.js b/toolkit/components/jsdownloads/test/unit/test_DownloadIntegration.js
new file mode 100644
index 000000000..31dd7c7a4
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadIntegration.js
@@ -0,0 +1,432 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the DownloadIntegration object.
+ */
+
+"use strict";
+
+// Globals
+
+/**
+ * Notifies the prompt observers and verify the expected downloads count.
+ *
+ * @param aIsPrivate
+ *        Flag to know is test private observers.
+ * @param aExpectedCount
+ *        the expected downloads count for quit and offline observers.
+ * @param aExpectedPBCount
+ *        the expected downloads count for private browsing observer.
+ */
+function notifyPromptObservers(aIsPrivate, aExpectedCount, aExpectedPBCount) {
+  let cancelQuit = Cc["@mozilla.org/supports-PRBool;1"].
+                   createInstance(Ci.nsISupportsPRBool);
+
+  // Notify quit application requested observer.
+  DownloadIntegration._testPromptDownloads = -1;
+  Services.obs.notifyObservers(cancelQuit, "quit-application-requested", null);
+  do_check_eq(DownloadIntegration._testPromptDownloads, aExpectedCount);
+
+  // Notify offline requested observer.
+  DownloadIntegration._testPromptDownloads = -1;
+  Services.obs.notifyObservers(cancelQuit, "offline-requested", null);
+  do_check_eq(DownloadIntegration._testPromptDownloads, aExpectedCount);
+
+  if (aIsPrivate) {
+    // Notify last private browsing requested observer.
+    DownloadIntegration._testPromptDownloads = -1;
+    Services.obs.notifyObservers(cancelQuit, "last-pb-context-exiting", null);
+    do_check_eq(DownloadIntegration._testPromptDownloads, aExpectedPBCount);
+  }
+
+  delete DownloadIntegration._testPromptDownloads;
+}
+
+// Tests
+
+/**
+ * Allows re-enabling the real download directory logic during one test.
+ */
+function allowDirectoriesInTest() {
+  DownloadIntegration.allowDirectories = true;
+  function cleanup() {
+    DownloadIntegration.allowDirectories = false;
+  }
+  do_register_cleanup(cleanup);
+  return cleanup;
+}
+
+XPCOMUtils.defineLazyGetter(this, "gStringBundle", function() {
+  return Services.strings.
+    createBundle("chrome://mozapps/locale/downloads/downloads.properties");
+});
+
+/**
+ * Tests that getSystemDownloadsDirectory returns an existing directory or
+ * creates a new directory depending on the platform. Instead of the real
+ * directory, this test is executed in the temporary directory so we can safely
+ * delete the created folder to check whether it is created again.
+ */
+add_task(function* test_getSystemDownloadsDirectory_exists_or_creates()
+{
+  let tempDir = Services.dirsvc.get("TmpD", Ci.nsIFile);
+  let downloadDir;
+
+  // OSX / Linux / Windows but not XP/2k
+  if (Services.appinfo.OS == "Darwin" ||
+      Services.appinfo.OS == "Linux" ||
+      (Services.appinfo.OS == "WINNT" &&
+       parseFloat(Services.sysinfo.getProperty("version")) >= 6)) {
+    downloadDir = yield DownloadIntegration.getSystemDownloadsDirectory();
+    do_check_eq(downloadDir, tempDir.path);
+    do_check_true(yield OS.File.exists(downloadDir));
+
+    let info = yield OS.File.stat(downloadDir);
+    do_check_true(info.isDir);
+  } else {
+    let targetPath = OS.Path.join(tempDir.path,
+                       gStringBundle.GetStringFromName("downloadsFolder"));
+    try {
+      yield OS.File.removeEmptyDir(targetPath);
+    } catch (e) {}
+    downloadDir = yield DownloadIntegration.getSystemDownloadsDirectory();
+    do_check_eq(downloadDir, targetPath);
+    do_check_true(yield OS.File.exists(downloadDir));
+
+    let info = yield OS.File.stat(downloadDir);
+    do_check_true(info.isDir);
+    yield OS.File.removeEmptyDir(targetPath);
+  }
+});
+
+/**
+ * Tests that the real directory returned by getSystemDownloadsDirectory is not
+ * the one that is used during unit tests. Since this is the actual downloads
+ * directory of the operating system, we don't try to delete it afterwards.
+ */
+add_task(function* test_getSystemDownloadsDirectory_real()
+{
+  let fakeDownloadDir = yield DownloadIntegration.getSystemDownloadsDirectory();
+
+  let cleanup = allowDirectoriesInTest();
+  let realDownloadDir = yield DownloadIntegration.getSystemDownloadsDirectory();
+  cleanup();
+
+  do_check_neq(fakeDownloadDir, realDownloadDir);
+});
+
+/**
+ * Tests that the getPreferredDownloadsDirectory returns a valid download
+ * directory string path.
+ */
+add_task(function* test_getPreferredDownloadsDirectory()
+{
+  let cleanupDirectories = allowDirectoriesInTest();
+
+  let folderListPrefName = "browser.download.folderList";
+  let dirPrefName = "browser.download.dir";
+  function cleanupPrefs() {
+    Services.prefs.clearUserPref(folderListPrefName);
+    Services.prefs.clearUserPref(dirPrefName);
+  }
+  do_register_cleanup(cleanupPrefs);
+
+  // Should return the system downloads directory.
+  Services.prefs.setIntPref(folderListPrefName, 1);
+  let systemDir = yield DownloadIntegration.getSystemDownloadsDirectory();
+  let downloadDir = yield DownloadIntegration.getPreferredDownloadsDirectory();
+  do_check_neq(downloadDir, "");
+  do_check_eq(downloadDir, systemDir);
+
+  // Should return the desktop directory.
+  Services.prefs.setIntPref(folderListPrefName, 0);
+  downloadDir = yield DownloadIntegration.getPreferredDownloadsDirectory();
+  do_check_neq(downloadDir, "");
+  do_check_eq(downloadDir, Services.dirsvc.get("Desk", Ci.nsIFile).path);
+
+  // Should return the system downloads directory because the dir preference
+  // is not set.
+  Services.prefs.setIntPref(folderListPrefName, 2);
+  downloadDir = yield DownloadIntegration.getPreferredDownloadsDirectory();
+  do_check_neq(downloadDir, "");
+  do_check_eq(downloadDir, systemDir);
+
+  // Should return the directory which is listed in the dir preference.
+  let time = (new Date()).getTime();
+  let tempDir = Services.dirsvc.get("TmpD", Ci.nsIFile);
+  tempDir.append(time);
+  Services.prefs.setComplexValue("browser.download.dir", Ci.nsIFile, tempDir);
+  downloadDir = yield DownloadIntegration.getPreferredDownloadsDirectory();
+  do_check_neq(downloadDir, "");
+  do_check_eq(downloadDir,  tempDir.path);
+  do_check_true(yield OS.File.exists(downloadDir));
+  yield OS.File.removeEmptyDir(tempDir.path);
+
+  // Should return the system downloads directory beacause the path is invalid
+  // in the dir preference.
+  tempDir = Services.dirsvc.get("TmpD", Ci.nsIFile);
+  tempDir.append("dir_not_exist");
+  tempDir.append(time);
+  Services.prefs.setComplexValue("browser.download.dir", Ci.nsIFile, tempDir);
+  downloadDir = yield DownloadIntegration.getPreferredDownloadsDirectory();
+  do_check_eq(downloadDir, systemDir);
+
+  // Should return the system downloads directory because the folderList
+  // preference is invalid
+  Services.prefs.setIntPref(folderListPrefName, 999);
+  downloadDir = yield DownloadIntegration.getPreferredDownloadsDirectory();
+  do_check_eq(downloadDir, systemDir);
+
+  cleanupPrefs();
+  cleanupDirectories();
+});
+
+/**
+ * Tests that the getTemporaryDownloadsDirectory returns a valid download
+ * directory string path.
+ */
+add_task(function* test_getTemporaryDownloadsDirectory()
+{
+  let cleanup = allowDirectoriesInTest();
+
+  let downloadDir = yield DownloadIntegration.getTemporaryDownloadsDirectory();
+  do_check_neq(downloadDir, "");
+
+  if ("nsILocalFileMac" in Ci) {
+    let preferredDownloadDir = yield DownloadIntegration.getPreferredDownloadsDirectory();
+    do_check_eq(downloadDir, preferredDownloadDir);
+  } else {
+    let tempDir = Services.dirsvc.get("TmpD", Ci.nsIFile);
+    do_check_eq(downloadDir, tempDir.path);
+  }
+
+  cleanup();
+});
+
+// Tests DownloadObserver
+
+/**
+ * Re-enables the default observers for the following tests.
+ *
+ * This takes effect the first time a DownloadList object is created, and lasts
+ * until this test file has completed.
+ */
+add_task(function* test_observers_setup()
+{
+  DownloadIntegration.allowObservers = true;
+  do_register_cleanup(function () {
+    DownloadIntegration.allowObservers = false;
+  });
+});
+
+/**
+ * Tests notifications prompts when observers are notified if there are public
+ * and private active downloads.
+ */
+add_task(function* test_notifications()
+{
+  for (let isPrivate of [false, true]) {
+    mustInterruptResponses();
+
+    let list = yield promiseNewList(isPrivate);
+    let download1 = yield promiseNewDownload(httpUrl("interruptible.txt"));
+    let download2 = yield promiseNewDownload(httpUrl("interruptible.txt"));
+    let download3 = yield promiseNewDownload(httpUrl("interruptible.txt"));
+    let promiseAttempt1 = download1.start();
+    let promiseAttempt2 = download2.start();
+    download3.start().catch(() => {});
+
+    // Add downloads to list.
+    yield list.add(download1);
+    yield list.add(download2);
+    yield list.add(download3);
+    // Cancel third download
+    yield download3.cancel();
+
+    notifyPromptObservers(isPrivate, 2, 2);
+
+    // Allow the downloads to complete.
+    continueResponses();
+    yield promiseAttempt1;
+    yield promiseAttempt2;
+
+    // Clean up.
+    yield list.remove(download1);
+    yield list.remove(download2);
+    yield list.remove(download3);
+  }
+});
+
+/**
+ * Tests that notifications prompts observers are not notified if there are no
+ * public or private active downloads.
+ */
+add_task(function* test_no_notifications()
+{
+  for (let isPrivate of [false, true]) {
+    let list = yield promiseNewList(isPrivate);
+    let download1 = yield promiseNewDownload(httpUrl("interruptible.txt"));
+    let download2 = yield promiseNewDownload(httpUrl("interruptible.txt"));
+    download1.start().catch(() => {});
+    download2.start().catch(() => {});
+
+    // Add downloads to list.
+    yield list.add(download1);
+    yield list.add(download2);
+
+    yield download1.cancel();
+    yield download2.cancel();
+
+    notifyPromptObservers(isPrivate, 0, 0);
+
+    // Clean up.
+    yield list.remove(download1);
+    yield list.remove(download2);
+  }
+});
+
+/**
+ * Tests notifications prompts when observers are notified if there are public
+ * and private active downloads at the same time.
+ */
+add_task(function* test_mix_notifications()
+{
+  mustInterruptResponses();
+
+  let publicList = yield promiseNewList();
+  let privateList = yield Downloads.getList(Downloads.PRIVATE);
+  let download1 = yield promiseNewDownload(httpUrl("interruptible.txt"));
+  let download2 = yield promiseNewDownload(httpUrl("interruptible.txt"));
+  let promiseAttempt1 = download1.start();
+  let promiseAttempt2 = download2.start();
+
+  // Add downloads to lists.
+  yield publicList.add(download1);
+  yield privateList.add(download2);
+
+  notifyPromptObservers(true, 2, 1);
+
+  // Allow the downloads to complete.
+  continueResponses();
+  yield promiseAttempt1;
+  yield promiseAttempt2;
+
+  // Clean up.
+  yield publicList.remove(download1);
+  yield privateList.remove(download2);
+});
+
+/**
+ * Tests suspending and resuming as well as going offline and then online again.
+ * The downloads should stop when suspending and start again when resuming.
+ */
+add_task(function* test_suspend_resume()
+{
+  // The default wake delay is 10 seconds, so set the wake delay to be much
+  // faster for these tests.
+  Services.prefs.setIntPref("browser.download.manager.resumeOnWakeDelay", 5);
+
+  let addDownload = function(list)
+  {
+    return Task.spawn(function* () {
+      let download = yield promiseNewDownload(httpUrl("interruptible.txt"));
+      download.start().catch(() => {});
+      list.add(download);
+      return download;
+    });
+  }
+
+  let publicList = yield promiseNewList();
+  let privateList = yield promiseNewList(true);
+
+  let download1 = yield addDownload(publicList);
+  let download2 = yield addDownload(publicList);
+  let download3 = yield addDownload(privateList);
+  let download4 = yield addDownload(privateList);
+  let download5 = yield addDownload(publicList);
+
+  // First, check that the downloads are all canceled when going to sleep.
+  Services.obs.notifyObservers(null, "sleep_notification", null);
+  do_check_true(download1.canceled);
+  do_check_true(download2.canceled);
+  do_check_true(download3.canceled);
+  do_check_true(download4.canceled);
+  do_check_true(download5.canceled);
+
+  // Remove a download. It should not be started again.
+  publicList.remove(download5);
+  do_check_true(download5.canceled);
+
+  // When waking up again, the downloads start again after the wake delay. To be
+  // more robust, don't check after a delay but instead just wait for the
+  // downloads to finish.
+  Services.obs.notifyObservers(null, "wake_notification", null);
+  yield download1.whenSucceeded();
+  yield download2.whenSucceeded();
+  yield download3.whenSucceeded();
+  yield download4.whenSucceeded();
+
+  // Downloads should no longer be canceled. However, as download5 was removed
+  // from the public list, it will not be restarted.
+  do_check_false(download1.canceled);
+  do_check_true(download5.canceled);
+
+  // Create four new downloads and check for going offline and then online again.
+
+  download1 = yield addDownload(publicList);
+  download2 = yield addDownload(publicList);
+  download3 = yield addDownload(privateList);
+  download4 = yield addDownload(privateList);
+
+  // Going offline should cancel the downloads.
+  Services.obs.notifyObservers(null, "network:offline-about-to-go-offline", null);
+  do_check_true(download1.canceled);
+  do_check_true(download2.canceled);
+  do_check_true(download3.canceled);
+  do_check_true(download4.canceled);
+
+  // Going back online should start the downloads again.
+  Services.obs.notifyObservers(null, "network:offline-status-changed", "online");
+  yield download1.whenSucceeded();
+  yield download2.whenSucceeded();
+  yield download3.whenSucceeded();
+  yield download4.whenSucceeded();
+
+  Services.prefs.clearUserPref("browser.download.manager.resumeOnWakeDelay");
+});
+
+/**
+ * Tests both the downloads list and the in-progress downloads are clear when
+ * private browsing observer is notified.
+ */
+add_task(function* test_exit_private_browsing()
+{
+  mustInterruptResponses();
+
+  let privateList = yield promiseNewList(true);
+  let download1 = yield promiseNewDownload(httpUrl("source.txt"));
+  let download2 = yield promiseNewDownload(httpUrl("interruptible.txt"));
+  let promiseAttempt1 = download1.start();
+  download2.start();
+
+  // Add downloads to list.
+  yield privateList.add(download1);
+  yield privateList.add(download2);
+
+  // Complete the download.
+  yield promiseAttempt1;
+
+  do_check_eq((yield privateList.getAll()).length, 2);
+
+  // Simulate exiting the private browsing.
+  yield new Promise(resolve => {
+    DownloadIntegration._testResolveClearPrivateList = resolve;
+    Services.obs.notifyObservers(null, "last-pb-context-exited", null);
+  });
+  delete DownloadIntegration._testResolveClearPrivateList;
+
+  do_check_eq((yield privateList.getAll()).length, 0);
+
+  continueResponses();
+});
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadLegacy.js b/toolkit/components/jsdownloads/test/unit/test_DownloadLegacy.js
new file mode 100644
index 000000000..dc6c18623
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadLegacy.js
@@ -0,0 +1,17 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the integration with legacy interfaces for downloads.
+ */
+
+"use strict";
+
+// Execution of common tests
+
+var gUseLegacySaver = true;
+
+var scriptFile = do_get_file("common_test_Download.js");
+Services.scriptloader.loadSubScript(NetUtil.newURI(scriptFile).spec);
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadList.js b/toolkit/components/jsdownloads/test/unit/test_DownloadList.js
new file mode 100644
index 000000000..71e880741
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadList.js
@@ -0,0 +1,564 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the DownloadList object.
+ */
+
+"use strict";
+
+// Globals
+
+/**
+ * Returns a PRTime in the past usable to add expirable visits.
+ *
+ * @note Expiration ignores any visit added in the last 7 days, but it's
+ *       better be safe against DST issues, by going back one day more.
+ */
+function getExpirablePRTime()
+{
+  let dateObj = new Date();
+  // Normalize to midnight
+  dateObj.setHours(0);
+  dateObj.setMinutes(0);
+  dateObj.setSeconds(0);
+  dateObj.setMilliseconds(0);
+  dateObj = new Date(dateObj.getTime() - 8 * 86400000);
+  return dateObj.getTime() * 1000;
+}
+
+/**
+ * Adds an expirable history visit for a download.
+ *
+ * @param aSourceUrl
+ *        String containing the URI for the download source, or null to use
+ *        httpUrl("source.txt").
+ *
+ * @return {Promise}
+ * @rejects JavaScript exception.
+ */
+function promiseExpirableDownloadVisit(aSourceUrl)
+{
+  let deferred = Promise.defer();
+  PlacesUtils.asyncHistory.updatePlaces(
+    {
+      uri: NetUtil.newURI(aSourceUrl || httpUrl("source.txt")),
+      visits: [{
+        transitionType: Ci.nsINavHistoryService.TRANSITION_DOWNLOAD,
+        visitDate: getExpirablePRTime(),
+      }]
+    },
+    {
+      handleError: function handleError(aResultCode, aPlaceInfo) {
+        let ex = new Components.Exception("Unexpected error in adding visits.",
+                                          aResultCode);
+        deferred.reject(ex);
+      },
+      handleResult: function () {},
+      handleCompletion: function handleCompletion() {
+        deferred.resolve();
+      }
+    });
+  return deferred.promise;
+}
+
+// Tests
+
+/**
+ * Checks the testing mechanism used to build different download lists.
+ */
+add_task(function* test_construction()
+{
+  let downloadListOne = yield promiseNewList();
+  let downloadListTwo = yield promiseNewList();
+  let privateDownloadListOne = yield promiseNewList(true);
+  let privateDownloadListTwo = yield promiseNewList(true);
+
+  do_check_neq(downloadListOne, downloadListTwo);
+  do_check_neq(privateDownloadListOne, privateDownloadListTwo);
+  do_check_neq(downloadListOne, privateDownloadListOne);
+});
+
+/**
+ * Checks the methods to add and retrieve items from the list.
+ */
+add_task(function* test_add_getAll()
+{
+  let list = yield promiseNewList();
+
+  let downloadOne = yield promiseNewDownload();
+  yield list.add(downloadOne);
+
+  let itemsOne = yield list.getAll();
+  do_check_eq(itemsOne.length, 1);
+  do_check_eq(itemsOne[0], downloadOne);
+
+  let downloadTwo = yield promiseNewDownload();
+  yield list.add(downloadTwo);
+
+  let itemsTwo = yield list.getAll();
+  do_check_eq(itemsTwo.length, 2);
+  do_check_eq(itemsTwo[0], downloadOne);
+  do_check_eq(itemsTwo[1], downloadTwo);
+
+  // The first snapshot should not have been modified.
+  do_check_eq(itemsOne.length, 1);
+});
+
+/**
+ * Checks the method to remove items from the list.
+ */
+add_task(function* test_remove()
+{
+  let list = yield promiseNewList();
+
+  yield list.add(yield promiseNewDownload());
+  yield list.add(yield promiseNewDownload());
+
+  let items = yield list.getAll();
+  yield list.remove(items[0]);
+
+  // Removing an item that was never added should not raise an error.
+  yield list.remove(yield promiseNewDownload());
+
+  items = yield list.getAll();
+  do_check_eq(items.length, 1);
+});
+
+/**
+ * Tests that the "add", "remove", and "getAll" methods on the global
+ * DownloadCombinedList object combine the contents of the global DownloadList
+ * objects for public and private downloads.
+ */
+add_task(function* test_DownloadCombinedList_add_remove_getAll()
+{
+  let publicList = yield promiseNewList();
+  let privateList = yield Downloads.getList(Downloads.PRIVATE);
+  let combinedList = yield Downloads.getList(Downloads.ALL);
+
+  let publicDownload = yield promiseNewDownload();
+  let privateDownload = yield Downloads.createDownload({
+    source: { url: httpUrl("source.txt"), isPrivate: true },
+    target: getTempFile(TEST_TARGET_FILE_NAME).path,
+  });
+
+  yield publicList.add(publicDownload);
+  yield privateList.add(privateDownload);
+
+  do_check_eq((yield combinedList.getAll()).length, 2);
+
+  yield combinedList.remove(publicDownload);
+  yield combinedList.remove(privateDownload);
+
+  do_check_eq((yield combinedList.getAll()).length, 0);
+
+  yield combinedList.add(publicDownload);
+  yield combinedList.add(privateDownload);
+
+  do_check_eq((yield publicList.getAll()).length, 1);
+  do_check_eq((yield privateList.getAll()).length, 1);
+  do_check_eq((yield combinedList.getAll()).length, 2);
+
+  yield publicList.remove(publicDownload);
+  yield privateList.remove(privateDownload);
+
+  do_check_eq((yield combinedList.getAll()).length, 0);
+});
+
+/**
+ * Checks that views receive the download add and remove notifications, and that
+ * adding and removing views works as expected, both for a normal and a combined
+ * list.
+ */
+add_task(function* test_notifications_add_remove()
+{
+  for (let isCombined of [false, true]) {
+    // Force creating a new list for both the public and combined cases.
+    let list = yield promiseNewList();
+    if (isCombined) {
+      list = yield Downloads.getList(Downloads.ALL);
+    }
+
+    let downloadOne = yield promiseNewDownload();
+    let downloadTwo = yield Downloads.createDownload({
+      source: { url: httpUrl("source.txt"), isPrivate: true },
+      target: getTempFile(TEST_TARGET_FILE_NAME).path,
+    });
+    yield list.add(downloadOne);
+    yield list.add(downloadTwo);
+
+    // Check that we receive add notifications for existing elements.
+    let addNotifications = 0;
+    let viewOne = {
+      onDownloadAdded: function (aDownload) {
+        // The first download to be notified should be the first that was added.
+        if (addNotifications == 0) {
+          do_check_eq(aDownload, downloadOne);
+        } else if (addNotifications == 1) {
+          do_check_eq(aDownload, downloadTwo);
+        }
+        addNotifications++;
+      },
+    };
+    yield list.addView(viewOne);
+    do_check_eq(addNotifications, 2);
+
+    // Check that we receive add notifications for new elements.
+    yield list.add(yield promiseNewDownload());
+    do_check_eq(addNotifications, 3);
+
+    // Check that we receive remove notifications.
+    let removeNotifications = 0;
+    let viewTwo = {
+      onDownloadRemoved: function (aDownload) {
+        do_check_eq(aDownload, downloadOne);
+        removeNotifications++;
+      },
+    };
+    yield list.addView(viewTwo);
+    yield list.remove(downloadOne);
+    do_check_eq(removeNotifications, 1);
+
+    // We should not receive remove notifications after the view is removed.
+    yield list.removeView(viewTwo);
+    yield list.remove(downloadTwo);
+    do_check_eq(removeNotifications, 1);
+
+    // We should not receive add notifications after the view is removed.
+    yield list.removeView(viewOne);
+    yield list.add(yield promiseNewDownload());
+    do_check_eq(addNotifications, 3);
+  }
+});
+
+/**
+ * Checks that views receive the download change notifications, both for a
+ * normal and a combined list.
+ */
+add_task(function* test_notifications_change()
+{
+  for (let isCombined of [false, true]) {
+    // Force creating a new list for both the public and combined cases.
+    let list = yield promiseNewList();
+    if (isCombined) {
+      list = yield Downloads.getList(Downloads.ALL);
+    }
+
+    let downloadOne = yield promiseNewDownload();
+    let downloadTwo = yield Downloads.createDownload({
+      source: { url: httpUrl("source.txt"), isPrivate: true },
+      target: getTempFile(TEST_TARGET_FILE_NAME).path,
+    });
+    yield list.add(downloadOne);
+    yield list.add(downloadTwo);
+
+    // Check that we receive change notifications.
+    let receivedOnDownloadChanged = false;
+    yield list.addView({
+      onDownloadChanged: function (aDownload) {
+        do_check_eq(aDownload, downloadOne);
+        receivedOnDownloadChanged = true;
+      },
+    });
+    yield downloadOne.start();
+    do_check_true(receivedOnDownloadChanged);
+
+    // We should not receive change notifications after a download is removed.
+    receivedOnDownloadChanged = false;
+    yield list.remove(downloadTwo);
+    yield downloadTwo.start();
+    do_check_false(receivedOnDownloadChanged);
+  }
+});
+
+/**
+ * Checks that the reference to "this" is correct in the view callbacks.
+ */
+add_task(function* test_notifications_this()
+{
+  let list = yield promiseNewList();
+
+  // Check that we receive change notifications.
+  let receivedOnDownloadAdded = false;
+  let receivedOnDownloadChanged = false;
+  let receivedOnDownloadRemoved = false;
+  let view = {
+    onDownloadAdded: function () {
+      do_check_eq(this, view);
+      receivedOnDownloadAdded = true;
+    },
+    onDownloadChanged: function () {
+      // Only do this check once.
+      if (!receivedOnDownloadChanged) {
+        do_check_eq(this, view);
+        receivedOnDownloadChanged = true;
+      }
+    },
+    onDownloadRemoved: function () {
+      do_check_eq(this, view);
+      receivedOnDownloadRemoved = true;
+    },
+  };
+  yield list.addView(view);
+
+  let download = yield promiseNewDownload();
+  yield list.add(download);
+  yield download.start();
+  yield list.remove(download);
+
+  // Verify that we executed the checks.
+  do_check_true(receivedOnDownloadAdded);
+  do_check_true(receivedOnDownloadChanged);
+  do_check_true(receivedOnDownloadRemoved);
+});
+
+/**
+ * Checks that download is removed on history expiration.
+ */
+add_task(function* test_history_expiration()
+{
+  mustInterruptResponses();
+
+  function cleanup() {
+    Services.prefs.clearUserPref("places.history.expiration.max_pages");
+  }
+  do_register_cleanup(cleanup);
+
+  // Set max pages to 0 to make the download expire.
+  Services.prefs.setIntPref("places.history.expiration.max_pages", 0);
+
+  let list = yield promiseNewList();
+  let downloadOne = yield promiseNewDownload();
+  let downloadTwo = yield promiseNewDownload(httpUrl("interruptible.txt"));
+
+  let deferred = Promise.defer();
+  let removeNotifications = 0;
+  let downloadView = {
+    onDownloadRemoved: function (aDownload) {
+      if (++removeNotifications == 2) {
+        deferred.resolve();
+      }
+    },
+  };
+  yield list.addView(downloadView);
+
+  // Work with one finished download and one canceled download.
+  yield downloadOne.start();
+  downloadTwo.start().catch(() => {});
+  yield downloadTwo.cancel();
+
+  // We must replace the visits added while executing the downloads with visits
+  // that are older than 7 days, otherwise they will not be expired.
+  yield PlacesTestUtils.clearHistory();
+  yield promiseExpirableDownloadVisit();
+  yield promiseExpirableDownloadVisit(httpUrl("interruptible.txt"));
+
+  // After clearing history, we can add the downloads to be removed to the list.
+  yield list.add(downloadOne);
+  yield list.add(downloadTwo);
+
+  // Force a history expiration.
+  Cc["@mozilla.org/places/expiration;1"]
+    .getService(Ci.nsIObserver).observe(null, "places-debug-start-expiration", -1);
+
+  // Wait for both downloads to be removed.
+  yield deferred.promise;
+
+  cleanup();
+});
+
+/**
+ * Checks all downloads are removed after clearing history.
+ */
+add_task(function* test_history_clear()
+{
+  let list = yield promiseNewList();
+  let downloadOne = yield promiseNewDownload();
+  let downloadTwo = yield promiseNewDownload();
+  yield list.add(downloadOne);
+  yield list.add(downloadTwo);
+
+  let deferred = Promise.defer();
+  let removeNotifications = 0;
+  let downloadView = {
+    onDownloadRemoved: function (aDownload) {
+      if (++removeNotifications == 2) {
+        deferred.resolve();
+      }
+    },
+  };
+  yield list.addView(downloadView);
+
+  yield downloadOne.start();
+  yield downloadTwo.start();
+
+  yield PlacesTestUtils.clearHistory();
+
+  // Wait for the removal notifications that may still be pending.
+  yield deferred.promise;
+});
+
+/**
+ * Tests the removeFinished method to ensure that it only removes
+ * finished downloads.
+ */
+add_task(function* test_removeFinished()
+{
+  let list = yield promiseNewList();
+  let downloadOne = yield promiseNewDownload();
+  let downloadTwo = yield promiseNewDownload();
+  let downloadThree = yield promiseNewDownload();
+  let downloadFour = yield promiseNewDownload();
+  yield list.add(downloadOne);
+  yield list.add(downloadTwo);
+  yield list.add(downloadThree);
+  yield list.add(downloadFour);
+
+  let deferred = Promise.defer();
+  let removeNotifications = 0;
+  let downloadView = {
+    onDownloadRemoved: function (aDownload) {
+      do_check_true(aDownload == downloadOne ||
+                    aDownload == downloadTwo ||
+                    aDownload == downloadThree);
+      do_check_true(removeNotifications < 3);
+      if (++removeNotifications == 3) {
+        deferred.resolve();
+      }
+    },
+  };
+  yield list.addView(downloadView);
+
+  // Start three of the downloads, but don't start downloadTwo, then set
+  // downloadFour to have partial data. All downloads except downloadFour
+  // should be removed.
+  yield downloadOne.start();
+  yield downloadThree.start();
+  yield downloadFour.start();
+  downloadFour.hasPartialData = true;
+
+  list.removeFinished();
+  yield deferred.promise;
+
+  let downloads = yield list.getAll()
+  do_check_eq(downloads.length, 1);
+});
+
+/**
+ * Tests the global DownloadSummary objects for the public, private, and
+ * combined download lists.
+ */
+add_task(function* test_DownloadSummary()
+{
+  mustInterruptResponses();
+
+  let publicList = yield promiseNewList();
+  let privateList = yield Downloads.getList(Downloads.PRIVATE);
+
+  let publicSummary = yield Downloads.getSummary(Downloads.PUBLIC);
+  let privateSummary = yield Downloads.getSummary(Downloads.PRIVATE);
+  let combinedSummary = yield Downloads.getSummary(Downloads.ALL);
+
+  // Add a public download that has succeeded.
+  let succeededPublicDownload = yield promiseNewDownload();
+  yield succeededPublicDownload.start();
+  yield publicList.add(succeededPublicDownload);
+
+  // Add a public download that has been canceled midway.
+  let canceledPublicDownload =
+      yield promiseNewDownload(httpUrl("interruptible.txt"));
+  canceledPublicDownload.start().catch(() => {});
+  yield promiseDownloadMidway(canceledPublicDownload);
+  yield canceledPublicDownload.cancel();
+  yield publicList.add(canceledPublicDownload);
+
+  // Add a public download that is in progress.
+  let inProgressPublicDownload =
+      yield promiseNewDownload(httpUrl("interruptible.txt"));
+  inProgressPublicDownload.start().catch(() => {});
+  yield promiseDownloadMidway(inProgressPublicDownload);
+  yield publicList.add(inProgressPublicDownload);
+
+  // Add a private download that is in progress.
+  let inProgressPrivateDownload = yield Downloads.createDownload({
+    source: { url: httpUrl("interruptible.txt"), isPrivate: true },
+    target: getTempFile(TEST_TARGET_FILE_NAME).path,
+  });
+  inProgressPrivateDownload.start().catch(() => {});
+  yield promiseDownloadMidway(inProgressPrivateDownload);
+  yield privateList.add(inProgressPrivateDownload);
+
+  // Verify that the summary includes the total number of bytes and the
+  // currently transferred bytes only for the downloads that are not stopped.
+  // For simplicity, we assume that after a download is added to the list, its
+  // current state is immediately propagated to the summary object, which is
+  // true in the current implementation, though it is not guaranteed as all the
+  // download operations may happen asynchronously.
+  do_check_false(publicSummary.allHaveStopped);
+  do_check_eq(publicSummary.progressTotalBytes, TEST_DATA_SHORT.length * 2);
+  do_check_eq(publicSummary.progressCurrentBytes, TEST_DATA_SHORT.length);
+
+  do_check_false(privateSummary.allHaveStopped);
+  do_check_eq(privateSummary.progressTotalBytes, TEST_DATA_SHORT.length * 2);
+  do_check_eq(privateSummary.progressCurrentBytes, TEST_DATA_SHORT.length);
+
+  do_check_false(combinedSummary.allHaveStopped);
+  do_check_eq(combinedSummary.progressTotalBytes, TEST_DATA_SHORT.length * 4);
+  do_check_eq(combinedSummary.progressCurrentBytes, TEST_DATA_SHORT.length * 2);
+
+  yield inProgressPublicDownload.cancel();
+
+  // Stopping the download should have excluded it from the summary.
+  do_check_true(publicSummary.allHaveStopped);
+  do_check_eq(publicSummary.progressTotalBytes, 0);
+  do_check_eq(publicSummary.progressCurrentBytes, 0);
+
+  do_check_false(privateSummary.allHaveStopped);
+  do_check_eq(privateSummary.progressTotalBytes, TEST_DATA_SHORT.length * 2);
+  do_check_eq(privateSummary.progressCurrentBytes, TEST_DATA_SHORT.length);
+
+  do_check_false(combinedSummary.allHaveStopped);
+  do_check_eq(combinedSummary.progressTotalBytes, TEST_DATA_SHORT.length * 2);
+  do_check_eq(combinedSummary.progressCurrentBytes, TEST_DATA_SHORT.length);
+
+  yield inProgressPrivateDownload.cancel();
+
+  // All the downloads should be stopped now.
+  do_check_true(publicSummary.allHaveStopped);
+  do_check_eq(publicSummary.progressTotalBytes, 0);
+  do_check_eq(publicSummary.progressCurrentBytes, 0);
+
+  do_check_true(privateSummary.allHaveStopped);
+  do_check_eq(privateSummary.progressTotalBytes, 0);
+  do_check_eq(privateSummary.progressCurrentBytes, 0);
+
+  do_check_true(combinedSummary.allHaveStopped);
+  do_check_eq(combinedSummary.progressTotalBytes, 0);
+  do_check_eq(combinedSummary.progressCurrentBytes, 0);
+});
+
+/**
+ * Checks that views receive the summary change notification.  This is tested on
+ * the combined summary when adding a public download, as we assume that if we
+ * pass the test in this case we will also pass it in the others.
+ */
+add_task(function* test_DownloadSummary_notifications()
+{
+  let list = yield promiseNewList();
+  let summary = yield Downloads.getSummary(Downloads.ALL);
+
+  let download = yield promiseNewDownload();
+  yield list.add(download);
+
+  // Check that we receive change notifications.
+  let receivedOnSummaryChanged = false;
+  yield summary.addView({
+    onSummaryChanged: function () {
+      receivedOnSummaryChanged = true;
+    },
+  });
+  yield download.start();
+  do_check_true(receivedOnSummaryChanged);
+});
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadStore.js b/toolkit/components/jsdownloads/test/unit/test_DownloadStore.js
new file mode 100644
index 000000000..3a23dfbe3
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadStore.js
@@ -0,0 +1,315 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the DownloadStore object.
+ */
+
+"use strict";
+
+// Globals
+
+XPCOMUtils.defineLazyModuleGetter(this, "DownloadStore",
+                                  "resource://gre/modules/DownloadStore.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "OS",
+                                  "resource://gre/modules/osfile.jsm")
+
+/**
+ * Returns a new DownloadList object with an associated DownloadStore.
+ *
+ * @param aStorePath
+ *        String pointing to the file to be associated with the DownloadStore,
+ *        or undefined to use a non-existing temporary file.  In this case, the
+ *        temporary file is deleted when the test file execution finishes.
+ *
+ * @return {Promise}
+ * @resolves Array [ Newly created DownloadList , associated DownloadStore ].
+ * @rejects JavaScript exception.
+ */
+function promiseNewListAndStore(aStorePath)
+{
+  return promiseNewList().then(function (aList) {
+    let path = aStorePath || getTempFile(TEST_STORE_FILE_NAME).path;
+    let store = new DownloadStore(aList, path);
+    return [aList, store];
+  });
+}
+
+// Tests
+
+/**
+ * Saves downloads to a file, then reloads them.
+ */
+add_task(function* test_save_reload()
+{
+  let [listForSave, storeForSave] = yield promiseNewListAndStore();
+  let [listForLoad, storeForLoad] = yield promiseNewListAndStore(
+                                                 storeForSave.path);
+
+  listForSave.add(yield promiseNewDownload(httpUrl("source.txt")));
+  listForSave.add(yield Downloads.createDownload({
+    source: { url: httpUrl("empty.txt"),
+              referrer: TEST_REFERRER_URL },
+    target: getTempFile(TEST_TARGET_FILE_NAME),
+  }));
+
+  // This PDF download should not be serialized because it never succeeds.
+  let pdfDownload = yield Downloads.createDownload({
+    source: { url: httpUrl("empty.txt"),
+              referrer: TEST_REFERRER_URL },
+    target: getTempFile(TEST_TARGET_FILE_NAME),
+    saver: "pdf",
+  });
+  listForSave.add(pdfDownload);
+
+  // If we used a callback to adjust the channel, the download should
+  // not be serialized because we can't recreate it across sessions.
+  let adjustedDownload = yield Downloads.createDownload({
+    source: { url: httpUrl("empty.txt"),
+              adjustChannel: () => Promise.resolve() },
+    target: getTempFile(TEST_TARGET_FILE_NAME),
+  });
+  listForSave.add(adjustedDownload);
+
+  let legacyDownload = yield promiseStartLegacyDownload();
+  yield legacyDownload.cancel();
+  listForSave.add(legacyDownload);
+
+  yield storeForSave.save();
+  yield storeForLoad.load();
+
+  // Remove the PDF and adjusted downloads because they should not appear here.
+  listForSave.remove(adjustedDownload);
+  listForSave.remove(pdfDownload);
+
+  let itemsForSave = yield listForSave.getAll();
+  let itemsForLoad = yield listForLoad.getAll();
+
+  do_check_eq(itemsForSave.length, itemsForLoad.length);
+
+  // Downloads should be reloaded in the same order.
+  for (let i = 0; i < itemsForSave.length; i++) {
+    // The reloaded downloads are different objects.
+    do_check_neq(itemsForSave[i], itemsForLoad[i]);
+
+    // The reloaded downloads have the same properties.
+    do_check_eq(itemsForSave[i].source.url,
+                itemsForLoad[i].source.url);
+    do_check_eq(itemsForSave[i].source.referrer,
+                itemsForLoad[i].source.referrer);
+    do_check_eq(itemsForSave[i].target.path,
+                itemsForLoad[i].target.path);
+    do_check_eq(itemsForSave[i].saver.toSerializable(),
+                itemsForLoad[i].saver.toSerializable());
+  }
+});
+
+/**
+ * Checks that saving an empty list deletes any existing file.
+ */
+add_task(function* test_save_empty()
+{
+  let [, store] = yield promiseNewListAndStore();
+
+  let createdFile = yield OS.File.open(store.path, { create: true });
+  yield createdFile.close();
+
+  yield store.save();
+
+  do_check_false(yield OS.File.exists(store.path));
+
+  // If the file does not exist, saving should not generate exceptions.
+  yield store.save();
+});
+
+/**
+ * Checks that loading from a missing file results in an empty list.
+ */
+add_task(function* test_load_empty()
+{
+  let [list, store] = yield promiseNewListAndStore();
+
+  do_check_false(yield OS.File.exists(store.path));
+
+  yield store.load();
+
+  let items = yield list.getAll();
+  do_check_eq(items.length, 0);
+});
+
+/**
+ * Loads downloads from a string in a predefined format.  The purpose of this
+ * test is to verify that the JSON format used in previous versions can be
+ * loaded, assuming the file is reloaded on the same platform.
+ */
+add_task(function* test_load_string_predefined()
+{
+  let [list, store] = yield promiseNewListAndStore();
+
+  // The platform-dependent file name should be generated dynamically.
+  let targetPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+  let filePathLiteral = JSON.stringify(targetPath);
+  let sourceUriLiteral = JSON.stringify(httpUrl("source.txt"));
+  let emptyUriLiteral = JSON.stringify(httpUrl("empty.txt"));
+  let referrerUriLiteral = JSON.stringify(TEST_REFERRER_URL);
+
+  let string = "{\"list\":[{\"source\":" + sourceUriLiteral + "," +
+                "\"target\":" + filePathLiteral + "}," +
+                "{\"source\":{\"url\":" + emptyUriLiteral + "," +
+                "\"referrer\":" + referrerUriLiteral + "}," +
+                "\"target\":" + filePathLiteral + "}]}";
+
+  yield OS.File.writeAtomic(store.path,
+                            new TextEncoder().encode(string),
+                            { tmpPath: store.path + ".tmp" });
+
+  yield store.load();
+
+  let items = yield list.getAll();
+
+  do_check_eq(items.length, 2);
+
+  do_check_eq(items[0].source.url, httpUrl("source.txt"));
+  do_check_eq(items[0].target.path, targetPath);
+
+  do_check_eq(items[1].source.url, httpUrl("empty.txt"));
+  do_check_eq(items[1].source.referrer, TEST_REFERRER_URL);
+  do_check_eq(items[1].target.path, targetPath);
+});
+
+/**
+ * Loads downloads from a well-formed JSON string containing unrecognized data.
+ */
+add_task(function* test_load_string_unrecognized()
+{
+  let [list, store] = yield promiseNewListAndStore();
+
+  // The platform-dependent file name should be generated dynamically.
+  let targetPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+  let filePathLiteral = JSON.stringify(targetPath);
+  let sourceUriLiteral = JSON.stringify(httpUrl("source.txt"));
+
+  let string = "{\"list\":[{\"source\":null," +
+                "\"target\":null}," +
+                "{\"source\":{\"url\":" + sourceUriLiteral + "}," +
+                "\"target\":{\"path\":" + filePathLiteral + "}," +
+                "\"saver\":{\"type\":\"copy\"}}]}";
+
+  yield OS.File.writeAtomic(store.path,
+                            new TextEncoder().encode(string),
+                            { tmpPath: store.path + ".tmp" });
+
+  yield store.load();
+
+  let items = yield list.getAll();
+
+  do_check_eq(items.length, 1);
+
+  do_check_eq(items[0].source.url, httpUrl("source.txt"));
+  do_check_eq(items[0].target.path, targetPath);
+});
+
+/**
+ * Loads downloads from a malformed JSON string.
+ */
+add_task(function* test_load_string_malformed()
+{
+  let [list, store] = yield promiseNewListAndStore();
+
+  let string = "{\"list\":[{\"source\":null,\"target\":null}," +
+                "{\"source\":{\"url\":\"about:blank\"}}}";
+
+  yield OS.File.writeAtomic(store.path, new TextEncoder().encode(string),
+                            { tmpPath: store.path + ".tmp" });
+
+  try {
+    yield store.load();
+    do_throw("Exception expected when JSON data is malformed.");
+  } catch (ex) {
+    if (ex.name != "SyntaxError") {
+      throw ex;
+    }
+    do_print("The expected SyntaxError exception was thrown.");
+  }
+
+  let items = yield list.getAll();
+
+  do_check_eq(items.length, 0);
+});
+
+/**
+ * Saves downloads with unknown properties to a file and then reloads
+ * them to ensure that these properties are preserved.
+ */
+add_task(function* test_save_reload_unknownProperties()
+{
+  let [listForSave, storeForSave] = yield promiseNewListAndStore();
+  let [listForLoad, storeForLoad] = yield promiseNewListAndStore(
+                                                 storeForSave.path);
+
+  let download1 = yield promiseNewDownload(httpUrl("source.txt"));
+  // startTime should be ignored as it is a known property, and error
+  // is ignored by serialization
+  download1._unknownProperties = { peanut: "butter",
+                                   orange: "marmalade",
+                                   startTime: 77,
+                                   error: { message: "Passed" } };
+  listForSave.add(download1);
+
+  let download2 = yield promiseStartLegacyDownload();
+  yield download2.cancel();
+  download2._unknownProperties = { number: 5, object: { test: "string" } };
+  listForSave.add(download2);
+
+  let download3 = yield Downloads.createDownload({
+    source: { url: httpUrl("empty.txt"),
+              referrer: TEST_REFERRER_URL,
+              source1: "download3source1",
+              source2: "download3source2" },
+    target: { path: getTempFile(TEST_TARGET_FILE_NAME).path,
+              target1: "download3target1",
+              target2: "download3target2" },
+    saver : { type: "copy",
+              saver1: "download3saver1",
+              saver2: "download3saver2" },
+  });
+  listForSave.add(download3);
+
+  yield storeForSave.save();
+  yield storeForLoad.load();
+
+  let itemsForSave = yield listForSave.getAll();
+  let itemsForLoad = yield listForLoad.getAll();
+
+  do_check_eq(itemsForSave.length, itemsForLoad.length);
+
+  do_check_eq(Object.keys(itemsForLoad[0]._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[0]._unknownProperties.peanut, "butter");
+  do_check_eq(itemsForLoad[0]._unknownProperties.orange, "marmalade");
+  do_check_false("startTime" in itemsForLoad[0]._unknownProperties);
+  do_check_false("error" in itemsForLoad[0]._unknownProperties);
+
+  do_check_eq(Object.keys(itemsForLoad[1]._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[1]._unknownProperties.number, 5);
+  do_check_eq(itemsForLoad[1]._unknownProperties.object.test, "string");
+
+  do_check_eq(Object.keys(itemsForLoad[2].source._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[2].source._unknownProperties.source1,
+              "download3source1");
+  do_check_eq(itemsForLoad[2].source._unknownProperties.source2,
+              "download3source2");
+
+  do_check_eq(Object.keys(itemsForLoad[2].target._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[2].target._unknownProperties.target1,
+              "download3target1");
+  do_check_eq(itemsForLoad[2].target._unknownProperties.target2,
+              "download3target2");
+
+  do_check_eq(Object.keys(itemsForLoad[2].saver._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[2].saver._unknownProperties.saver1,
+              "download3saver1");
+  do_check_eq(itemsForLoad[2].saver._unknownProperties.saver2,
+              "download3saver2");
+});
diff --git a/toolkit/components/jsdownloads/test/unit/test_Downloads.js b/toolkit/components/jsdownloads/test/unit/test_Downloads.js
new file mode 100644
index 000000000..2027beee1
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/test_Downloads.js
@@ -0,0 +1,194 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the functions located directly in the "Downloads" object.
+ */
+
+"use strict";
+
+// Tests
+
+/**
+ * Tests that the createDownload function exists and can be called.  More
+ * detailed tests are implemented separately for the DownloadCore module.
+ */
+add_task(function* test_createDownload()
+{
+  // Creates a simple Download object without starting the download.
+  yield Downloads.createDownload({
+    source: { url: "about:blank" },
+    target: { path: getTempFile(TEST_TARGET_FILE_NAME).path },
+    saver: { type: "copy" },
+  });
+});
+
+/**
+ * Tests createDownload for private download.
+ */
+add_task(function* test_createDownload_private()
+{
+  let download = yield Downloads.createDownload({
+    source: { url: "about:blank", isPrivate: true },
+    target: { path: getTempFile(TEST_TARGET_FILE_NAME).path },
+    saver: { type: "copy" }
+  });
+  do_check_true(download.source.isPrivate);
+});
+
+/**
+ * Tests createDownload for normal (public) download.
+ */
+add_task(function* test_createDownload_public()
+{
+  let tempPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+  let download = yield Downloads.createDownload({
+    source: { url: "about:blank", isPrivate: false },
+    target: { path: tempPath },
+    saver: { type: "copy" }
+  });
+  do_check_false(download.source.isPrivate);
+
+  download = yield Downloads.createDownload({
+    source: { url: "about:blank" },
+    target: { path: tempPath },
+    saver: { type: "copy" }
+  });
+  do_check_false(download.source.isPrivate);
+});
+
+/**
+ * Tests createDownload for a pdf saver throws if only given a url.
+ */
+add_task(function* test_createDownload_pdf()
+{
+  let download = yield Downloads.createDownload({
+    source: { url: "about:blank" },
+    target: { path: getTempFile(TEST_TARGET_FILE_NAME).path },
+    saver: { type: "pdf" },
+  });
+
+  try {
+    yield download.start();
+    do_throw("The download should have failed.");
+  } catch (ex) {
+    if (!(ex instanceof Downloads.Error) || !ex.becauseSourceFailed) {
+      throw ex;
+    }
+  }
+
+  do_check_false(download.succeeded);
+  do_check_true(download.stopped);
+  do_check_false(download.canceled);
+  do_check_true(download.error !== null);
+  do_check_true(download.error.becauseSourceFailed);
+  do_check_false(download.error.becauseTargetFailed);
+  do_check_false(yield OS.File.exists(download.target.path));
+});
+
+/**
+ * Tests "fetch" with nsIURI and nsIFile as arguments.
+ */
+add_task(function* test_fetch_uri_file_arguments()
+{
+  let targetFile = getTempFile(TEST_TARGET_FILE_NAME);
+  yield Downloads.fetch(NetUtil.newURI(httpUrl("source.txt")), targetFile);
+  yield promiseVerifyContents(targetFile.path, TEST_DATA_SHORT);
+});
+
+/**
+ * Tests "fetch" with DownloadSource and DownloadTarget as arguments.
+ */
+add_task(function* test_fetch_object_arguments()
+{
+  let targetPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+  yield Downloads.fetch({ url: httpUrl("source.txt") }, { path: targetPath });
+  yield promiseVerifyContents(targetPath, TEST_DATA_SHORT);
+});
+
+/**
+ * Tests "fetch" with string arguments.
+ */
+add_task(function* test_fetch_string_arguments()
+{
+  let targetPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+  yield Downloads.fetch(httpUrl("source.txt"), targetPath);
+  yield promiseVerifyContents(targetPath, TEST_DATA_SHORT);
+
+  targetPath = getTempFile(TEST_TARGET_FILE_NAME).path;
+  yield Downloads.fetch(new String(httpUrl("source.txt")),
+                        new String(targetPath));
+  yield promiseVerifyContents(targetPath, TEST_DATA_SHORT);
+});
+
+/**
+ * Tests that the getList function returns the same list when called multiple
+ * times with the same argument, but returns different lists when called with
+ * different arguments.  More detailed tests are implemented separately for the
+ * DownloadList module.
+ */
+add_task(function* test_getList()
+{
+  let publicListOne = yield Downloads.getList(Downloads.PUBLIC);
+  let privateListOne = yield Downloads.getList(Downloads.PRIVATE);
+
+  let publicListTwo = yield Downloads.getList(Downloads.PUBLIC);
+  let privateListTwo = yield Downloads.getList(Downloads.PRIVATE);
+
+  do_check_eq(publicListOne, publicListTwo);
+  do_check_eq(privateListOne, privateListTwo);
+
+  do_check_neq(publicListOne, privateListOne);
+});
+
+/**
+ * Tests that the getSummary function returns the same summary when called
+ * multiple times with the same argument, but returns different summaries when
+ * called with different arguments.  More detailed tests are implemented
+ * separately for the DownloadSummary object in the DownloadList module.
+ */
+add_task(function* test_getSummary()
+{
+  let publicSummaryOne = yield Downloads.getSummary(Downloads.PUBLIC);
+  let privateSummaryOne = yield Downloads.getSummary(Downloads.PRIVATE);
+
+  let publicSummaryTwo = yield Downloads.getSummary(Downloads.PUBLIC);
+  let privateSummaryTwo = yield Downloads.getSummary(Downloads.PRIVATE);
+
+  do_check_eq(publicSummaryOne, publicSummaryTwo);
+  do_check_eq(privateSummaryOne, privateSummaryTwo);
+
+  do_check_neq(publicSummaryOne, privateSummaryOne);
+});
+
+/**
+ * Tests that the getSystemDownloadsDirectory returns a non-empty download
+ * directory string.
+ */
+add_task(function* test_getSystemDownloadsDirectory()
+{
+  let downloadDir = yield Downloads.getSystemDownloadsDirectory();
+  do_check_neq(downloadDir, "");
+});
+
+/**
+ * Tests that the getPreferredDownloadsDirectory returns a non-empty download
+ * directory string.
+ */
+add_task(function* test_getPreferredDownloadsDirectory()
+{
+  let downloadDir = yield Downloads.getPreferredDownloadsDirectory();
+  do_check_neq(downloadDir, "");
+});
+
+/**
+ * Tests that the getTemporaryDownloadsDirectory returns a non-empty download
+ * directory string.
+ */
+add_task(function* test_getTemporaryDownloadsDirectory()
+{
+  let downloadDir = yield Downloads.getTemporaryDownloadsDirectory();
+  do_check_neq(downloadDir, "");
+});
diff --git a/toolkit/components/jsdownloads/test/unit/test_PrivateTemp.js b/toolkit/components/jsdownloads/test/unit/test_PrivateTemp.js
new file mode 100644
index 000000000..1308e9782
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/test_PrivateTemp.js
@@ -0,0 +1,24 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/*
+ * The temporary directory downloads saves to, should be only readable
+ * for the current user.
+ */
+add_task(function* test_private_temp() {
+
+  let download = yield promiseStartExternalHelperAppServiceDownload(
+                                                         httpUrl("empty.txt"));
+
+  yield promiseDownloadStopped(download);
+
+  var targetFile = Cc['@mozilla.org/file/local;1'].createInstance(Ci.nsIFile);
+  targetFile.initWithPath(download.target.path);
+
+  // 488 is the decimal value of 0o700.
+  equal(targetFile.parent.permissions, 448);
+});
diff --git a/toolkit/components/jsdownloads/test/unit/xpcshell.ini b/toolkit/components/jsdownloads/test/unit/xpcshell.ini
new file mode 100644
index 000000000..8de554540
--- /dev/null
+++ b/toolkit/components/jsdownloads/test/unit/xpcshell.ini
@@ -0,0 +1,19 @@
+[DEFAULT]
+head = head.js
+tail =
+skip-if = toolkit == 'android'
+
+# Note: The "tail.js" file is not defined in the "tail" key because it calls
+#       the "add_test_task" function, that does not work properly in tail files.
+support-files =
+  common_test_Download.js
+
+[test_DownloadCore.js]
+[test_DownloadImport.js]
+[test_DownloadIntegration.js]
+[test_DownloadLegacy.js]
+[test_DownloadList.js]
+[test_Downloads.js]
+[test_DownloadStore.js]
+[test_PrivateTemp.js]
+skip-if = os != 'linux'