diff -r 000000000000 -r 6474c204b198 browser/devtools/webconsole/test/browser_webconsole_cached_autocomplete.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/webconsole/test/browser_webconsole_cached_autocomplete.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,125 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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/. */
+
+// Tests that the cached autocomplete results are used when the new
+// user input is a subset of the existing completion results.
+
+const TEST_URI = "data:text/html;charset=utf8,<p>test cached autocompletion results";
+
+let testDriver;
+
+function test() {
+  requestLongerTimeout(2);
+  addTab(TEST_URI);
+  browser.addEventListener("load", function onLoad() {
+    browser.removeEventListener("load", onLoad, true);
+    openConsole(null, function(hud) {
+      testDriver = testCompletion(hud);
+      testDriver.next();
+    });
+  }, true);
+}
+
+function testNext() {
+  executeSoon(function() {
+    testDriver.next();
+  });
+}
+
+function testCompletion(hud) {
+  let jsterm = hud.jsterm;
+  let input = jsterm.inputNode;
+  let popup = jsterm.autocompletePopup;
+
+  // Test if 'doc' gives 'document'
+  input.value = "doc";
+  input.setSelectionRange(3, 3);
+  jsterm.complete(jsterm.COMPLETE_HINT_ONLY, testNext);
+  yield undefined;
+
+  is(input.value, "doc", "'docu' completion (input.value)");
+  is(jsterm.completeNode.value, "   ument", "'docu' completion (completeNode)");
+
+  // Test typing 'window.'.
+  input.value = "window.";
+  input.setSelectionRange(7, 7);
+  jsterm.complete(jsterm.COMPLETE_HINT_ONLY, testNext);
+  yield undefined;
+
+  ok(popup.getItems().length > 0, "'window.' gave a list of suggestions")
+
+  content.wrappedJSObject.docfoobar = true;
+
+  // Test typing 'window.doc'.
+  input.value = "window.doc";
+  input.setSelectionRange(10, 10);
+  jsterm.complete(jsterm.COMPLETE_HINT_ONLY, testNext);
+  yield undefined;
+
+  let newItems = popup.getItems();
+  ok(newItems.every(function(item) {
+       return item.label != "docfoobar";
+     }), "autocomplete cached results do not contain docfoobar. list has not been updated");
+
+  // Test that backspace does not cause a request to the server
+  input.value = "window.do";
+  input.setSelectionRange(9, 9);
+  jsterm.complete(jsterm.COMPLETE_HINT_ONLY, testNext);
+  yield undefined;
+
+  newItems = popup.getItems();
+  ok(newItems.every(function(item) {
+       return item.label != "docfoobar";
+     }), "autocomplete cached results do not contain docfoobar. list has not been updated");
+
+  delete content.wrappedJSObject.docfoobar;
+
+  // Test if 'window.getC' gives 'getComputedStyle'
+  input.value = "window."
+  input.setSelectionRange(7, 7);
+  jsterm.complete(jsterm.COMPLETE_HINT_ONLY, testNext);
+  yield undefined;
+  input.value = "window.getC";
+  input.setSelectionRange(11, 11);
+  jsterm.complete(jsterm.COMPLETE_HINT_ONLY, testNext);
+  yield undefined;
+  newItems = popup.getItems();
+  ok(!newItems.every(function(item) {
+       return item.label != "getComputedStyle";
+     }), "autocomplete results do contain getComputedStyle");
+
+  // Test if 'dump(d' gives non-zero results
+  input.value = "dump(d";
+  input.setSelectionRange(6, 6);
+  jsterm.complete(jsterm.COMPLETE_HINT_ONLY, testNext);
+  yield undefined;
+
+  ok(popup.getItems().length > 0, "'dump(d' gives non-zero results");
+
+  // Test that 'dump(window.)' works.
+  input.value = "dump(window.)";
+  input.setSelectionRange(12, 12);
+  jsterm.complete(jsterm.COMPLETE_HINT_ONLY, testNext);
+  yield undefined;
+
+  content.wrappedJSObject.docfoobar = true;
+
+  // Make sure 'dump(window.doc)' does not contain 'docfoobar'.
+  input.value = "dump(window.doc)";
+  input.setSelectionRange(15, 15);
+  jsterm.complete(jsterm.COMPLETE_HINT_ONLY, testNext);
+  yield undefined;
+
+  newItems = popup.getItems();
+  ok(newItems.every(function(item) {
+       return item.label != "docfoobar";
+     }), "autocomplete cached results do not contain docfoobar. list has not been updated");
+
+  delete content.wrappedJSObject.docfoobar;
+
+  testDriver = null;
+  executeSoon(finishTest);
+  yield undefined;
+}