9 files changed, 896 insertions, 0 deletions
diff --git a/dom/downloads/tests/clear_all_done_helper.js b/dom/downloads/tests/clear_all_done_helper.js
new file mode 100644
index 000000000..62fa1a2f3
--- /dev/null
+++ b/dom/downloads/tests/clear_all_done_helper.js
@@ -0,0 +1,67 @@
+/**
+ * A helper to clear out the existing downloads known to the mozDownloadManager
+ * / downloads.js.
+ *
+ * It exists because previously mozDownloadManager.clearAllDone() thought that
+ * when it returned that all the completed downloads would be cleared out.  It
+ * was wrong and this led to various intermittent test failurse.  In discussion
+ * on https://bugzil.la/979446#c13 and onwards, it was decided that
+ * clearAllDone() was in the wrong and that the jsdownloads API it depends on
+ * was not going to change to make it be in the right.
+ *
+ * The existing uses of clearAllDone() in tests seemed to be about:
+ * - Exploding if there was somehow still a download in progress
+ * - Clearing out the download list at the start of a test so that calls to
+ *   getDownloads() wouldn't have to worry about existing downloads, etc.
+ *
+ * From discussion, the right way to handle clearing is to wait for the expected
+ * removal events to occur for the existing downloads.  So that's what we do.
+ * We still generate a test failure if there are any in-progress downloads.
+ *
+ * @param {Boolean} [getDownloads=false]
+ *   If true, invoke getDownloads after clearing the download list and return
+ *   its value.
+ */
+function clearAllDoneHelper(getDownloads) {
+  var clearedPromise = new Promise(function(resolve, reject) {
+    function gotDownloads(downloads) {
+      // If there are no downloads, we're already done.
+      if (downloads.length === 0) {
+        resolve();
+        return;
+      }
+
+      // Track the set of expected downloads that will be finalized.
+      var expectedIds = new Set();
+      function changeHandler(evt) {
+        var download = evt.download;
+        if (download.state === "finalized") {
+          expectedIds.delete(download.id);
+          if (expectedIds.size === 0) {
+            resolve();
+          }
+        }
+      }
+      downloads.forEach(function(download) {
+        if (download.state === "downloading") {
+          ok(false, "A download is still active: " + download.path);
+          reject("Active download");
+        }
+        download.onstatechange = changeHandler;
+        expectedIds.add(download.id);
+      });
+      navigator.mozDownloadManager.clearAllDone();
+    }
+    function gotBadNews(err) {
+      ok(false, "Problem clearing all downloads: " + err);
+      reject(err);
+    }
+    navigator.mozDownloadManager.getDownloads().then(gotDownloads, gotBadNews);
+ });
+ if (!getDownloads) {
+   return clearedPromise;
+ }
+ return clearedPromise.then(function() {
+   return navigator.mozDownloadManager.getDownloads();
+ });
+}
diff --git a/dom/downloads/tests/mochitest.ini b/dom/downloads/tests/mochitest.ini
new file mode 100644
index 000000000..e13e4d887
--- /dev/null
+++ b/dom/downloads/tests/mochitest.ini
@@ -0,0 +1,15 @@
+[DEFAULT]
+# The actual requirement for mozDownloadManager is MOZ_GONK because of
+# the nsIVolumeService dependency.  Until https://bugzil.la/1130264 is
+# addressed, there is no way for mulet to run these tests.
+run-if = toolkit == 'gonk'
+support-files =
+  serve_file.sjs
+  clear_all_done_helper.js
+
+[test_downloads_navigator_object.html]
+[test_downloads_basic.html]
+[test_downloads_large.html]
+[test_downloads_bad_file.html]
+[test_downloads_pause_remove.html]
+[test_downloads_pause_resume.html]
diff --git a/dom/downloads/tests/serve_file.sjs b/dom/downloads/tests/serve_file.sjs
new file mode 100644
index 000000000..d0171d7ca
--- /dev/null
+++ b/dom/downloads/tests/serve_file.sjs
@@ -0,0 +1,170 @@
+// Serves a file with a given mime type and size at an optionally given rate.
+
+function getQuery(request) {
+  var query = {};
+  request.queryString.split('&').forEach(function (val) {
+    var [name, value] = val.split('=');
+    query[name] = unescape(value);
+  });
+  return query;
+}
+
+function handleResponse() {
+  // Is this a rate limited response?
+  if (this.state.rate > 0) {
+    // Calculate how many bytes we have left to send.
+    var bytesToWrite = this.state.totalBytes - this.state.sentBytes;
+
+    // Do we have any bytes left to send? If not we'll just fall thru and
+    // cancel our repeating timer and finalize the response.
+    if (bytesToWrite > 0) {
+      // Figure out how many bytes to send, based on the rate limit.
+      bytesToWrite =
+        (bytesToWrite > this.state.rate) ? this.state.rate : bytesToWrite;
+
+      for (let i = 0; i < bytesToWrite; i++) {
+        try {
+          this.response.bodyOutputStream.write("0", 1);
+        } catch (e) {
+          // Connection was closed by client.
+          if (e == Components.results.NS_ERROR_NOT_AVAILABLE) {
+            // There's no harm in calling this multiple times.
+            this.response.finish();
+
+            // It's possible that our timer wasn't cancelled in time
+            // and we'll be called again.
+            if (this.timer) {
+              this.timer.cancel();
+              this.timer = null;
+            }
+
+            return;
+          }
+        }
+      }
+
+      // Update the number of bytes we've sent to the client.
+      this.state.sentBytes += bytesToWrite;
+
+      // Wait until the next call to do anything else.
+      return;
+    }
+  }
+  else {
+    // Not rate limited, write it all out.
+    for (let i = 0; i < this.state.totalBytes; i++) {
+      this.response.write("0");
+    }
+  }
+
+  // Finalize the response.
+  this.response.finish();
+
+  // All done sending, go ahead and cancel our repeating timer.
+  this.timer.cancel();
+
+  // Clear the timer.
+  this.timer = null;
+}
+
+function handleRequest(request, response) {
+  var query = getQuery(request);
+
+  // sending at a specific rate requires our response to be asynchronous so
+  // we handle all requests asynchronously. See handleResponse().
+  response.processAsync();
+
+  // Default status when responding.
+  var version = "1.1";
+  var statusCode = 200;
+  var description = "OK";
+
+  // Default values for content type, size and rate.
+  var contentType = "text/plain";
+  var contentRange = null;
+  var size = 1024;
+  var rate = 0;
+
+  // optional content type to be used by our response.
+  if ("contentType" in query) {
+    contentType = query["contentType"];
+  }
+
+  // optional size (in bytes) for generated file.
+  if ("size" in query) {
+    size = parseInt(query["size"]);
+  }
+
+  // optional range request check.
+  if (request.hasHeader("range")) {
+    version = "1.1";
+    statusCode = 206;
+    description = "Partial Content";
+
+    // We'll only support simple range byte style requests.
+    var [offset, total] = request.getHeader("range").slice("bytes=".length).split("-");
+    // Enforce valid Number values.
+    offset = parseInt(offset);
+    offset = isNaN(offset) ? 0 : offset;
+    // Same.
+    total = parseInt(total);
+    total = isNaN(total) ? 0 : total;
+
+    // We'll need to original total size as part of the Content-Range header
+    // value in our response.
+    var originalSize = size;
+
+    // If we have a total size requested, we must make sure to send that number
+    // of bytes only (minus the start offset).
+    if (total && total < size) {
+      size = total - offset;
+    } else if (offset) {
+      // Looks like we just have a byte offset to deal with.
+      size = size - offset;
+    }
+
+    // We specifically need to add a Content-Range header to all responses for
+    // requests that include a range request header.
+    contentRange = "bytes " + offset + "-" + (size - 1) + "/" + originalSize;
+  }
+
+  // optional rate (in bytes/s) at which to send the file.
+  if ("rate" in query) {
+    rate = parseInt(query["rate"]);
+  }
+
+  // The context for the responseHandler.
+  var context = {
+    response: response,
+    state: {
+      contentType: contentType,
+      totalBytes: size,
+      sentBytes: 0,
+      rate: rate
+    },
+    timer: null
+  };
+
+  // The notify implementation for the timer.
+  context.notify = handleResponse.bind(context);
+
+  context.timer =
+    Components.classes["@mozilla.org/timer;1"]
+              .createInstance(Components.interfaces.nsITimer);
+
+  // generate the content.
+  response.setStatusLine(version, statusCode, description);
+  response.setHeader("Content-Type", contentType, false);
+  if (contentRange) {
+    response.setHeader("Content-Range", contentRange, false);
+  }
+  response.setHeader("Content-Length", size.toString(), false);
+
+  // initialize the timer and start writing out the response.
+  context.timer.initWithCallback(
+    context,
+    1000,
+    Components.interfaces.nsITimer.TYPE_REPEATING_SLACK
+  );
+
+}
diff --git a/dom/downloads/tests/test_downloads_bad_file.html b/dom/downloads/tests/test_downloads_bad_file.html
new file mode 100644
index 000000000..a2b3992e6
--- /dev/null
+++ b/dom/downloads/tests/test_downloads_bad_file.html
@@ -0,0 +1,93 @@
+<!DOCTYPE html>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=960749
+-->
+<head>
+  <title>Test for Bug 960749 Downloads API</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=960749">Mozilla Bug 960749</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<a href="serve_file.sjs?contentType=application/octet-stream&size=1024" download=".&lt;.EVIL.&gt;\ / : * ? &quot; |file.bin" id="download1">Download #1</a>
+<pre id="test">
+<script class="testbody" type="text/javascript;version=1.7">
+
+// Testing a simple download, waiting for it to be done.
+
+SimpleTest.waitForExplicitFinish();
+
+var index = -1;
+var expected = "_.EVIL.__ _ _ _ _ _ _file.bin";
+
+function next() {
+  index += 1;
+  if (index >= steps.length) {
+    ok(false, "Shouldn't get here!");
+    return;
+  }
+  try {
+    steps[index]();
+  } catch(ex) {
+    ok(false, "Caught exception", ex);
+  }
+}
+
+function checkTargetFilename(download) {
+  ok(download.path.endsWith(expected),
+     "Download path leaf name '" + download.path +
+     "' should match '" + expected + "' filename.");
+
+  SimpleTest.finish();
+}
+
+function downloadChange(evt) {
+  var download = evt.download;
+
+  if (download.state === "succeeded") {
+    checkTargetFilename(download);
+  }
+}
+
+function downloadStart(evt) {
+  var download = evt.download;
+  download.onstatechange = downloadChange;
+}
+
+var steps = [
+  // Start by setting the pref to true.
+  function() {
+    SpecialPowers.pushPrefEnv({
+      set: [["dom.mozDownloads.enabled", true]]
+    }, next);
+  },
+
+  // Setup the event listeners.
+  function() {
+    SpecialPowers.pushPermissions([
+      {type: "downloads", allow: true, context: document}
+    ], function() {
+      navigator.mozDownloadManager.ondownloadstart = downloadStart;
+      next();
+    });
+  },
+
+  // Click on the <a download> to start the download.
+  function() {
+    document.getElementById("download1").click();
+  }
+];
+
+next();
+
+</script>
+</pre>
+</body>
+</html>
+
diff --git a/dom/downloads/tests/test_downloads_basic.html b/dom/downloads/tests/test_downloads_basic.html
new file mode 100644
index 000000000..051a1faa1
--- /dev/null
+++ b/dom/downloads/tests/test_downloads_basic.html
@@ -0,0 +1,128 @@
+<!DOCTYPE html>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=938023
+-->
+<head>
+  <title>Test for Bug 938023 Downloads API</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=938023">Mozilla Bug 938023</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<a href="serve_file.sjs?contentType=application/octet-stream&size=1024" download="test.bin" id="download1">Download #1</a>
+<pre id="test">
+<script class="testbody" type="text/javascript;version=1.7">
+
+// Testing a simple download, waiting for it to be done.
+
+SimpleTest.waitForExplicitFinish();
+
+var index = -1;
+var todayDate = new Date();
+var baseServeURL = "http://mochi.test:8888/tests/dom/downloads/tests/";
+var lastKnownCurrentBytes = 0;
+
+function next() {
+  index += 1;
+  if (index >= steps.length) {
+    ok(false, "Shouldn't get here!");
+    return;
+  }
+  try {
+    steps[index]();
+  } catch(ex) {
+    ok(false, "Caught exception", ex);
+  }
+}
+
+function checkConsistentDownloadAttributes(download) {
+  var href = document.getElementById("download1").getAttribute("href");
+  var expectedServeURL = baseServeURL + href;
+  var destinationRegEx = /test\(?[0-9]*\)?\.bin$/;
+
+  // bug 945323: Download path isn't honoring download attribute
+  ok(destinationRegEx.test(download.path),
+     "Download path '" + download.path +
+     "' should match '" + destinationRegEx + "' regexp.");
+
+  ok(download.startTime >= todayDate,
+     "Download start time should be greater than or equal to today");
+
+  is(download.error, null, "Download does not have an error");
+
+  is(download.url, expectedServeURL,
+     "Download URL = " + expectedServeURL);
+  ok(download.id !== null, "Download id is defined");
+  is(download.contentType, "application/octet-stream",
+     "Download content type is application/octet-stream");
+}
+
+function downloadChange(evt) {
+  var download = evt.download;
+  checkConsistentDownloadAttributes(download);
+  is(download.totalBytes, 1024, "Download total size is 1024 bytes");
+
+  if (download.state === "succeeded") {
+    is(download.currentBytes, 1024, "Download current size is 1024 bytes");
+    SimpleTest.finish();
+  } else if (download.state === "downloading") {
+    // Note that this case may or may not trigger, depending on whether the
+    // download is initially reported with 0 bytes (we should happen) or with
+    // 1024 bytes (we should not happen).  If we do happen, an additional 8
+    // TEST-PASS events should be logged.
+    ok(download.currentBytes > lastKnownCurrentBytes,
+       "Download current size is larger than last download change event");
+    lastKnownCurrentBytes = download.currentBytes;
+  } else {
+    ok(false, "Unexpected download state = " + download.state);
+  }
+}
+
+function downloadStart(evt) {
+  var download = evt.download;
+  checkConsistentDownloadAttributes(download);
+
+  // We used to check that the currentBytes was 0.  This was incorrect.  It
+  // is very common to first hear about the download already at 1024 bytes.
+  is(download.state, "downloading", "Download state is downloading");
+
+  download.onstatechange = downloadChange;
+}
+
+var steps = [
+  // Start by setting the pref to true.
+  function() {
+    SpecialPowers.pushPrefEnv({
+      set: [["dom.mozDownloads.enabled", true]]
+    }, next);
+  },
+
+  // Setup the event listeners.
+  function() {
+    SpecialPowers.pushPermissions([
+      {type: "downloads", allow: true, context: document}
+    ], function() {
+      navigator.mozDownloadManager.ondownloadstart = downloadStart;
+      next();
+    });
+  },
+
+  // Click on the <a download> to start the download.
+  function() {
+    document.getElementById("download1").click();
+  }
+];
+
+next();
+
+</script>
+</pre>
+</body>
+</html>
+
diff --git a/dom/downloads/tests/test_downloads_large.html b/dom/downloads/tests/test_downloads_large.html
new file mode 100644
index 000000000..9f7f73c19
--- /dev/null
+++ b/dom/downloads/tests/test_downloads_large.html
@@ -0,0 +1,110 @@
+<!DOCTYPE html>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=938023
+-->
+<head>
+  <title>Test for Bug 938023 Downloads API</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="clear_all_done_helper.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=938023">Mozilla Bug 938023</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<a href="serve_file.sjs?contentType=application/octet-stream&size=102400" download="test.bin" id="download1">Large Download</a>
+<pre id="test">
+<script class="testbody" type="text/javascript;version=1.7">
+
+// Testing downloading a file, then checking getDownloads() and clearAllDone().
+
+SimpleTest.waitForExplicitFinish();
+
+var index = -1;
+
+function next(args) {
+  index += 1;
+  if (index >= steps.length) {
+    ok(false, "Shouldn't get here!");
+    return;
+  }
+  try {
+    steps[index](args);
+  } catch(ex) {
+    ok(false, "Caught exception", ex);
+  }
+}
+
+// Catch all error function.
+function error() {
+  ok(false, "API failure");
+  SimpleTest.finish();
+}
+
+function getDownloads(downloads) {
+  ok(downloads.length == 1, "One downloads after getDownloads");
+  clearAllDoneHelper(true).then(clearAllDone, error);
+}
+
+function clearAllDone(downloads) {
+  ok(downloads.length == 0, "No downloads after clearAllDone");
+  SimpleTest.finish();
+}
+
+function downloadChange(evt) {
+  var download = evt.download;
+
+  if (download.state == "succeeded") {
+    ok(download.totalBytes == 102400, "Download size is 100k bytes.");
+    navigator.mozDownloadManager.getDownloads().then(getDownloads, error);
+  }
+}
+
+var steps = [
+  // Start by setting the pref to true.
+  function() {
+    SpecialPowers.pushPrefEnv({
+      set: [["dom.mozDownloads.enabled", true]]
+    }, next);
+  },
+
+  // Setup permission and clear current list.
+  function() {
+    SpecialPowers.pushPermissions([
+      {type: "downloads", allow: true, context: document}
+    ], function() {
+      clearAllDoneHelper(true).then(next, error);
+    });
+  },
+
+  function(downloads) {
+    ok(downloads.length == 0, "Start with an empty download list.");
+    next();
+  },
+
+  // Setup the event listeners.
+  function() {
+    navigator.mozDownloadManager.ondownloadstart =
+      function(evt) {
+        ok(true, "Download started");
+        evt.download.addEventListener("statechange", downloadChange);
+      }
+    next();
+  },
+
+  // Click on the <a download> to start the download.
+  function() {
+    document.getElementById("download1").click();
+  }
+];
+
+next();
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/downloads/tests/test_downloads_navigator_object.html b/dom/downloads/tests/test_downloads_navigator_object.html
new file mode 100644
index 000000000..1c38388b7
--- /dev/null
+++ b/dom/downloads/tests/test_downloads_navigator_object.html
@@ -0,0 +1,75 @@
+<!DOCTYPE html>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=938023
+-->
+<head>
+  <title>Test for Bug 938023 Downloads API</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=938023">Mozilla Bug 938023</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+<iframe></iframe>
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript;version=1.7">
+
+SimpleTest.waitForExplicitFinish();
+
+var index = -1;
+
+function next() {
+  index += 1;
+  if (index >= steps.length) {
+    ok(false, "Shouldn't get here!");
+    return;
+  }
+  try {
+    steps[index]();
+  } catch(ex) {
+    ok(false, "Caught exception", ex);
+  }
+}
+
+var steps = [
+  // Start by setting the pref to true.
+  function() {
+    SpecialPowers.pushPrefEnv({
+      set: [["dom.mozDownloads.enabled", true]]
+    }, next);
+  },
+
+  function() {
+    SpecialPowers.pushPermissions([
+      {type: "downloads", allow: 0, context: document}
+    ], function() {
+      is(frames[0].navigator.mozDownloadManager, null, "navigator.mozDownloadManager is null when the page doesn't have permissions");
+      next();
+    });
+  },
+
+  function() {
+    SpecialPowers.pushPrefEnv({
+      set: [["dom.mozDownloads.enabled", false]]
+    }, function() {
+      is(navigator.mozDownloadManager, undefined, "navigator.mozDownloadManager is undefined");
+      next();
+    });
+  },
+
+  function() {
+    SimpleTest.finish();
+  }
+];
+
+next();
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/downloads/tests/test_downloads_pause_remove.html b/dom/downloads/tests/test_downloads_pause_remove.html
new file mode 100644
index 000000000..3b410a667
--- /dev/null
+++ b/dom/downloads/tests/test_downloads_pause_remove.html
@@ -0,0 +1,117 @@
+<!DOCTYPE html>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=938023
+-->
+<head>
+  <title>Test for Bug 938023 Downloads API</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="clear_all_done_helper.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=938023">Mozilla Bug 938023</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<a href="serve_file.sjs?contentType=application/octet-stream&size=102400&rate=1024" download="test.bin" id="download1">Large Download</a>
+<pre id="test">
+<script class="testbody" type="text/javascript;version=1.7">
+
+// Testing pausing a download and then removing it.
+
+SimpleTest.waitForExplicitFinish();
+
+var index = -1;
+
+function next(args) {
+  index += 1;
+  if (index >= steps.length) {
+    ok(false, "Shouldn't get here!");
+    return;
+  }
+  try {
+    steps[index](args);
+  } catch(ex) {
+    ok(false, "Caught exception", ex);
+  }
+}
+
+var pausing = false;
+
+// Catch all error function.
+function error() {
+  ok(false, "API failure");
+  SimpleTest.finish();
+}
+
+function checkDownloadList(downloads) {
+  ok(downloads.length == 0, "No downloads left");
+  SimpleTest.finish();
+}
+
+function checkRemoved(download) {
+  ok(download.state == "finalized", "Download removed.");
+  navigator.mozDownloadManager.getDownloads()
+           .then(checkDownloadList, error);
+}
+
+function downloadChange(evt) {
+  var download = evt.download;
+
+  if (download.state == "downloading" && !pausing) {
+    pausing = true;
+    download.pause();
+  } else if (download.state == "stopped") {
+    ok(pausing, "Download stopped by pause()");
+    navigator.mozDownloadManager.remove(download)
+             .then(checkRemoved, error);
+  }
+}
+
+var steps = [
+  // Start by setting the pref to true.
+  function() {
+    SpecialPowers.pushPrefEnv({
+      set: [["dom.mozDownloads.enabled", true]]
+    }, next);
+  },
+
+  // Setup permission and clear current list.
+  function() {
+    SpecialPowers.pushPermissions([
+      {type: "downloads", allow: true, context: document}
+    ], function() {
+      clearAllDoneHelper(true).then(next, error);
+    });
+  },
+
+  function(downloads) {
+    ok(downloads.length == 0, "Start with an empty download list.");
+    next();
+  },
+
+  // Setup the event listeners.
+  function() {
+    navigator.mozDownloadManager.ondownloadstart =
+      function(evt) {
+        ok(true, "Download started");
+        evt.download.addEventListener("statechange", downloadChange);
+      }
+    next();
+  },
+
+  // Click on the <a download> to start the download.
+  function() {
+    document.getElementById("download1").click();
+  }
+];
+
+next();
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/downloads/tests/test_downloads_pause_resume.html b/dom/downloads/tests/test_downloads_pause_resume.html
new file mode 100644
index 000000000..76e249e5a
--- /dev/null
+++ b/dom/downloads/tests/test_downloads_pause_resume.html
@@ -0,0 +1,121 @@
+<!DOCTYPE html>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=938023
+-->
+<head>
+  <title>Test for Bug 938023 Downloads API</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="clear_all_done_helper.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=938023">Mozilla Bug 938023</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<a href="serve_file.sjs?contentType=application/octet-stream&size=102400&rate=1024" download="test.bin" id="download1">Large Download</a>
+<pre id="test">
+<script class="testbody" type="text/javascript;version=1.7">
+
+// Testing pausing a download and then resuming it.
+
+SimpleTest.waitForExplicitFinish();
+
+var index = -1;
+
+function next(args) {
+  index += 1;
+  if (index >= steps.length) {
+    ok(false, "Shouldn't get here!");
+    return;
+  }
+  try {
+    steps[index](args);
+  } catch(ex) {
+    ok(false, "Caught exception", ex);
+  }
+}
+
+var pausing = false;
+var resuming = false;
+
+// Catch all error function.
+function error() {
+  ok(false, "API failure");
+  SimpleTest.finish();
+}
+
+function checkDownloadList(downloads) {
+  ok(downloads.length == 0, "No downloads left");
+  SimpleTest.finish();
+}
+
+function checkResumeSucceeded(download) {
+  ok(download.state == "succeeded", "Download resumed successfully.");
+  clearAllDoneHelper(true).then(checkDownloadList, error);
+}
+
+function downloadChange(evt) {
+  var download = evt.download;
+
+  info("got download event, state: " + download.state +
+       " current bytes: " + download.currentBytes +
+       " pausing?: " + pausing + " resuming?: " + resuming);
+  if (download.state == "downloading" && !pausing) {
+    pausing = true;
+    download.pause();
+  } else if (download.state == "stopped" && !resuming) {
+    resuming = true;
+    ok(pausing, "Download stopped by pause()");
+    download.resume()
+            .then(function() { checkResumeSucceeded(download); }, error);
+  }
+}
+
+var steps = [
+  // Start by setting the pref to true.
+  function() {
+    SpecialPowers.pushPrefEnv({
+      set: [["dom.mozDownloads.enabled", true]]
+    }, next);
+  },
+
+  // Setup permission and clear current list.
+  function() {
+    SpecialPowers.pushPermissions([
+      {type: "downloads", allow: true, context: document}
+    ], function() {
+      clearAllDoneHelper(true).then(next, error);
+    });
+  },
+
+  function(downloads) {
+    ok(downloads.length == 0, "Start with an empty download list.");
+    next();
+  },
+
+  // Setup the event listeners.
+  function() {
+    navigator.mozDownloadManager.ondownloadstart =
+      function(evt) {
+        ok(true, "Download started");
+        evt.download.addEventListener("statechange", downloadChange);
+      }
+    next();
+  },
+
+  // Click on the <a download> to start the download.
+  function() {
+    document.getElementById("download1").click();
+  }
+];
+
+next();
+
+</script>
+</pre>
+</body>
+</html>