1 files changed, 53 insertions, 0 deletions
diff --git a/toolkit/components/reader/test/browser_readerMode_hidden_nodes.js b/toolkit/components/reader/test/browser_readerMode_hidden_nodes.js
new file mode 100644
index 000000000..b73eab58d
--- /dev/null
+++ b/toolkit/components/reader/test/browser_readerMode_hidden_nodes.js
@@ -0,0 +1,53 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that the reader mode button appears and works properly on
+ * reader-able content.
+ */
+const TEST_PREFS = [
+  ["reader.parse-on-load.enabled", true],
+  ["browser.reader.detectedFirstArticle", false],
+];
+
+const TEST_PATH = getRootDirectory(gTestPath).replace("chrome://mochitests/content", "http://example.com");
+
+var readerButton = document.getElementById("reader-mode-button");
+
+add_task(function* test_reader_button() {
+  registerCleanupFunction(function() {
+    // Reset test prefs.
+    TEST_PREFS.forEach(([name, value]) => {
+      Services.prefs.clearUserPref(name);
+    });
+    while (gBrowser.tabs.length > 1) {
+      gBrowser.removeCurrentTab();
+    }
+  });
+
+  // Set required test prefs.
+  TEST_PREFS.forEach(([name, value]) => {
+    Services.prefs.setBoolPref(name, value);
+  });
+
+  let tab = gBrowser.selectedTab = gBrowser.addTab();
+  is_element_hidden(readerButton, "Reader mode button is not present on a new tab");
+  // Point tab to a test page that is not reader-able due to hidden nodes.
+  let url = TEST_PATH + "readerModeArticleHiddenNodes.html";
+  let paintPromise = ContentTask.spawn(tab.linkedBrowser, "", function() {
+    return new Promise(resolve => {
+      addEventListener("DOMContentLoaded", function onDCL() {
+        removeEventListener("DOMContentLoaded", onDCL);
+        addEventListener("MozAfterPaint", function onPaint() {
+          removeEventListener("MozAfterPaint", onPaint);
+          resolve();
+        });
+      });
+    });
+  });
+  tab.linkedBrowser.loadURI(url);
+  yield paintPromise;
+
+  is_element_hidden(readerButton, "Reader mode button is still not present on tab with unreadable content.");
+});