diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_scripts-switching-02.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_scripts-switching-02.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,187 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Make sure that switching the displayed source in the UI works as advertised.
+ */
+
+const TAB_URL = EXAMPLE_URL + "doc_script-switching-02.html";
+
+let gTab, gDebuggee, gPanel, gDebugger;
+let gEditor, gSources;
+
+function test() {
+  initDebugger(TAB_URL).then(([aTab, aDebuggee, aPanel]) => {
+    gTab = aTab;
+    gDebuggee = aDebuggee;
+    gPanel = aPanel;
+    gDebugger = gPanel.panelWin;
+    gEditor = gDebugger.DebuggerView.editor;
+    gSources = gDebugger.DebuggerView.Sources;
+
+    waitForSourceAndCaretAndScopes(gPanel, "-02.js", 1)
+      .then(testSourcesDisplay)
+      .then(testSwitchPaused1)
+      .then(testSwitchPaused2)
+      .then(testSwitchRunning)
+      .then(() => resumeDebuggerThenCloseAndFinish(gPanel))
+      .then(null, aError => {
+        ok(false, "Got an error: " + aError.message + "\n" + aError.stack);
+      });
+
+    gDebuggee.firstCall();
+  });
+}
+
+let gLabel1 = "code_script-switching-01.js";
+let gLabel2 = "code_script-switching-02.js";
+let gParams = "?foo=bar,baz|lol";
+
+function testSourcesDisplay() {
+  let deferred = promise.defer();
+
+  is(gSources.itemCount, 2,
+    "Found the expected number of sources.");
+
+  ok(gSources.containsValue(EXAMPLE_URL + gLabel1),
+    "First source url is incorrect.");
+  ok(gSources.containsValue(EXAMPLE_URL + gLabel2 + gParams),
+    "Second source url is incorrect.");
+
+  ok(gSources.getItemForAttachment(e => e.label == gLabel1),
+    "First source label is incorrect.");
+  ok(gSources.getItemForAttachment(e => e.label == gLabel2),
+    "Second source label is incorrect.");
+
+  ok(gSources.selectedItem,
+    "There should be a selected item in the sources pane.");
+  is(gSources.selectedValue, EXAMPLE_URL + gLabel2 + gParams,
+    "The selected value is the sources pane is incorrect.");
+
+  is(gEditor.getText().search(/firstCall/), -1,
+    "The first source is not displayed.");
+  is(gEditor.getText().search(/debugger/), 172,
+    "The second source is displayed.");
+
+  ok(isCaretPos(gPanel, 1),
+    "Editor caret location is correct.");
+
+  // The editor's debug location takes a tick to update.
+  executeSoon(() => {
+    is(gEditor.getDebugLocation(), 0,
+      "Editor debugger location is correct.");
+    ok(gEditor.hasLineClass(0, "debug-line"),
+      "The debugged line is highlighted appropriately.");
+
+    waitForDebuggerEvents(gPanel, gDebugger.EVENTS.SOURCE_SHOWN).then(deferred.resolve);
+    gSources.selectedItem = e => e.attachment.label == gLabel1;
+  });
+
+  return deferred.promise;
+}
+
+function testSwitchPaused1() {
+  let deferred = promise.defer();
+
+  ok(gSources.selectedItem,
+    "There should be a selected item in the sources pane.");
+  is(gSources.selectedValue, EXAMPLE_URL + gLabel1,
+    "The selected value is the sources pane is incorrect.");
+
+  is(gEditor.getText().search(/firstCall/), 118,
+    "The first source is displayed.");
+  is(gEditor.getText().search(/debugger/), -1,
+    "The second source is not displayed.");
+
+  // The editor's debug location takes a tick to update.
+  executeSoon(() => {
+    ok(isCaretPos(gPanel, 1),
+      "Editor caret location is correct.");
+
+    is(gEditor.getDebugLocation(), null,
+      "Editor debugger location is correct.");
+    ok(!gEditor.hasLineClass(5, "debug-line"),
+      "The debugged line highlight was removed.");
+
+    waitForDebuggerEvents(gPanel, gDebugger.EVENTS.SOURCE_SHOWN).then(deferred.resolve);
+    gSources.selectedItem = e => e.attachment.label == gLabel2;
+  });
+
+  return deferred.promise;
+}
+
+function testSwitchPaused2() {
+  let deferred = promise.defer();
+
+  ok(gSources.selectedItem,
+    "There should be a selected item in the sources pane.");
+  is(gSources.selectedValue, EXAMPLE_URL + gLabel2 + gParams,
+    "The selected value is the sources pane is incorrect.");
+
+  is(gEditor.getText().search(/firstCall/), -1,
+    "The first source is not displayed.");
+  is(gEditor.getText().search(/debugger/), 172,
+    "The second source is displayed.");
+
+  // The editor's debug location takes a tick to update.
+  executeSoon(() => {
+    ok(isCaretPos(gPanel, 1),
+      "Editor caret location is correct.");
+    is(gEditor.getDebugLocation(), 0,
+      "Editor debugger location is correct.");
+    ok(gEditor.hasLineClass(0, "debug-line"),
+      "The debugged line is highlighted appropriately.");
+
+    // Step out three times.
+    waitForThreadEvents(gPanel, "paused").then(() => {
+      waitForThreadEvents(gPanel, "paused").then(() => {
+        waitForDebuggerEvents(gPanel, gDebugger.EVENTS.SOURCE_SHOWN).then(deferred.resolve);
+        gDebugger.gThreadClient.stepOut();
+      });
+      gDebugger.gThreadClient.stepOut();
+    });
+    gDebugger.gThreadClient.stepOut();
+  });
+
+  return deferred.promise;
+}
+
+function testSwitchRunning() {
+  let deferred = promise.defer();
+
+  ok(gSources.selectedItem,
+    "There should be a selected item in the sources pane.");
+  is(gSources.selectedValue, EXAMPLE_URL + gLabel1,
+    "The selected value is the sources pane is incorrect.");
+
+  is(gEditor.getText().search(/firstCall/), 118,
+    "The first source is displayed.");
+  is(gEditor.getText().search(/debugger/), -1,
+    "The second source is not displayed.");
+
+  // The editor's debug location takes a tick to update.
+  executeSoon(() => {
+    ok(isCaretPos(gPanel, 1),
+      "Editor caret location is correct.");
+    is(gEditor.getDebugLocation(), 0,
+      "Editor debugger location is correct.");
+    ok(gEditor.hasLineClass(0, "debug-line"),
+      "The debugged line is highlighted appropriately.");
+
+    deferred.resolve();
+  });
+
+  return deferred.promise;
+}
+
+registerCleanupFunction(function() {
+  gTab = null;
+  gDebuggee = null;
+  gPanel = null;
+  gDebugger = null;
+  gEditor = null;
+  gSources = null;
+  gLabel1 = null;
+  gLabel2 = null;
+  gParams = null;
+});