diff -r 000000000000 -r 6474c204b198 browser/devtools/commandline/test/browser_gcli_history.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/commandline/test/browser_gcli_history.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2012, Mozilla Foundation and contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+'use strict';
+// <INJECTED SOURCE:START>
+
+// THIS FILE IS GENERATED FROM SOURCE IN THE GCLI PROJECT
+// DO NOT EDIT IT DIRECTLY
+
+var exports = {};
+
+var TEST_URI = "data:text/html;charset=utf-8,<p id='gcli-input'>gcli-testHistory.js</p>";
+
+function test() {
+  return Task.spawn(function() {
+    let options = yield helpers.openTab(TEST_URI);
+    yield helpers.openToolbar(options);
+    gcli.addItems(mockCommands.items);
+
+    yield helpers.runTests(options, exports);
+
+    gcli.removeItems(mockCommands.items);
+    yield helpers.closeToolbar(options);
+    yield helpers.closeTab(options);
+  }).then(finish, helpers.handleError);
+}
+
+// <INJECTED SOURCE:END>
+
+// var assert = require('../testharness/assert');
+var History = require('gcli/ui/history').History;
+
+exports.testSimpleHistory = function (options) {
+  var history = new History({});
+  history.add('foo');
+  history.add('bar');
+  assert.is(history.backward(), 'bar');
+  assert.is(history.backward(), 'foo');
+
+  // Adding to the history again moves us back to the start of the history.
+  history.add('quux');
+  assert.is(history.backward(), 'quux');
+  assert.is(history.backward(), 'bar');
+  assert.is(history.backward(), 'foo');
+};
+
+exports.testBackwardsPastIndex = function (options) {
+  var history = new History({});
+  history.add('foo');
+  history.add('bar');
+  assert.is(history.backward(), 'bar');
+  assert.is(history.backward(), 'foo');
+
+  // Moving backwards past recorded history just keeps giving you the last
+  // item.
+  assert.is(history.backward(), 'foo');
+};
+
+exports.testForwardsPastIndex = function (options) {
+  var history = new History({});
+  history.add('foo');
+  history.add('bar');
+  assert.is(history.backward(), 'bar');
+  assert.is(history.backward(), 'foo');
+
+  // Going forward through the history again.
+  assert.is(history.forward(), 'bar');
+
+  // 'Present' time.
+  assert.is(history.forward(), '');
+
+  // Going to the 'future' just keeps giving us the empty string.
+  assert.is(history.forward(), '');
+};