diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_pretty-print-01.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_pretty-print-01.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,84 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Make sure that clicking the pretty print button prettifies the source.
+ */
+
+const TAB_URL = EXAMPLE_URL + "doc_pretty-print.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;
+
+    waitForSourceShown(gPanel, "code_ugly.js")
+      .then(testSourceIsUgly)
+      .then(() => {
+        const finished = waitForSourceShown(gPanel, "code_ugly.js");
+        clickPrettyPrintButton();
+        testProgressBarShown();
+        return finished;
+      })
+      .then(testSourceIsPretty)
+      .then(testEditorShown)
+      .then(testSourceIsStillPretty)
+      .then(() => closeDebuggerAndFinish(gPanel))
+      .then(null, aError => {
+        ok(false, "Got an error: " + DevToolsUtils.safeErrorString(aError));
+      });
+  });
+}
+
+function testSourceIsUgly() {
+  ok(!gEditor.getText().contains("\n  "),
+     "The source shouldn't be pretty printed yet.");
+}
+
+function clickPrettyPrintButton() {
+  gDebugger.document.getElementById("pretty-print").click();
+}
+
+function testProgressBarShown() {
+  const deck = gDebugger.document.getElementById("editor-deck");
+  is(deck.selectedIndex, 2, "The progress bar should be shown");
+}
+
+function testSourceIsPretty() {
+  ok(gEditor.getText().contains("\n  "),
+     "The source should be pretty printed.")
+}
+
+function testEditorShown() {
+  const deck = gDebugger.document.getElementById("editor-deck");
+  is(deck.selectedIndex, 0, "The editor should be shown");
+}
+
+function testSourceIsStillPretty() {
+  const deferred = promise.defer();
+
+  const { source } = gSources.selectedItem.attachment;
+  gDebugger.DebuggerController.SourceScripts.getText(source).then(([, text]) => {
+    ok(text.contains("\n  "),
+       "Subsequent calls to getText return the pretty printed source.");
+    deferred.resolve();
+  });
+
+  return deferred.promise;
+}
+
+registerCleanupFunction(function() {
+  gTab = null;
+  gDebuggee = null;
+  gPanel = null;
+  gDebugger = null;
+  gEditor = null;
+  gSources = null;
+});