diff -r 000000000000 -r 6474c204b198 browser/devtools/commandline/test/browser_cmd_jsb.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/commandline/test/browser_cmd_jsb.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,87 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Tests that the jsb command works as it should
+
+const TEST_URI = "http://example.com/browser/browser/devtools/commandline/" +
+                 "test/browser_cmd_jsb_script.jsi";
+
+function test() {
+  return Task.spawn(testTask).then(finish, helpers.handleError);
+}
+
+function testTask() {
+  let options = yield helpers.openTab("about:blank");
+  yield helpers.openToolbar(options);
+
+  let deferred = promise.defer();
+  let scratchpadWin = null;
+  let scratchpad = null;
+
+  let observer = {
+    onReady: function() {
+      scratchpad.removeObserver(observer);
+
+      let result = scratchpad.getText();
+      result = result.replace(/[\r\n]]*/g, "\n");
+      let correct = "function somefunc() {\n" +
+                "  if (true) // Some comment\n" +
+                "  doSomething();\n" +
+                "  for (let n = 0; n < 500; n++) {\n" +
+                "    if (n % 2 == 1) {\n" +
+                "      console.log(n);\n" +
+                "      console.log(n + 1);\n" +
+                "    }\n" +
+                "  }\n" +
+                "}";
+      is(result, correct, "JS has been correctly prettified");
+
+      if (scratchpadWin) {
+        scratchpadWin.close();
+        scratchpadWin = null;
+      }
+      deferred.resolve();
+    },
+  };
+
+  let onLoad = function GDT_onLoad() {
+    scratchpadWin.removeEventListener("load", onLoad, false);
+    scratchpad = scratchpadWin.Scratchpad;
+
+    scratchpad.addObserver(observer);
+  };
+
+  let onNotify = function(subject, topic, data) {
+    if (topic == "domwindowopened") {
+      Services.ww.unregisterNotification(onNotify);
+
+      scratchpadWin = subject.QueryInterface(Ci.nsIDOMWindow);
+      scratchpadWin.addEventListener("load", onLoad, false);
+    }
+  };
+
+  Services.ww.registerNotification(onNotify);
+
+  helpers.audit(options, [
+    {
+      setup: 'jsb',
+      check: {
+        input:  'jsb',
+        hints:     ' <url> [options]',
+        markup: 'VVV',
+        status: 'ERROR'
+      }
+    },
+    {
+      setup: 'jsb ' + TEST_URI,
+      // Should result in a new window, which should fire onReady (eventually)
+      exec: {
+      }
+    }
+  ]);
+
+  yield deferred.promise;
+
+  yield helpers.closeToolbar(options);
+  yield helpers.closeTab(options);
+}