diff -r 000000000000 -r 6474c204b198 browser/devtools/scratchpad/test/browser_scratchpad_throw_output.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/scratchpad/test/browser_scratchpad_throw_output.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,53 @@
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+
+function test()
+{
+  waitForExplicitFinish();
+
+  gBrowser.selectedTab = gBrowser.addTab();
+  gBrowser.selectedBrowser.addEventListener("load", function onLoad() {
+    gBrowser.selectedBrowser.removeEventListener("load", onLoad, true);
+    openScratchpad(testThrowOutput);
+  }, true);
+
+  content.location = "data:text/html;charset=utf8,<p>Test throw outputs in Scratchpad</p>";
+}
+
+function testThrowOutput()
+{
+  let scratchpad = gScratchpadWindow.Scratchpad, tests = [];
+
+  let falsyValues = ["false", "0", "-0", "null", "undefined", "Infinity",
+                      "-Infinity", "NaN"];
+  falsyValues.forEach(function(value) {
+    tests.push({
+      method: "display",
+      code: "throw " + value + ";",
+      result: "throw " + value + ";\n/*\nException: " + value + "\n*/",
+      label: "Correct exception message for '" + value + "' is shown"
+    });
+  });
+
+  let server = Cu.import("resource://gre/modules/devtools/dbg-server.jsm", {})
+               .DebuggerServer;
+
+  let longLength = server.LONG_STRING_LENGTH + 1;
+  let longString = new Array(longLength).join("a");
+  let shortedString = longString.substring(0, server.LONG_STRING_INITIAL_LENGTH) +
+                      "\u2026";
+
+  tests.push({
+    method: "display",
+    code: "throw (new Array(" + longLength + ").join('a'));",
+    result: "throw (new Array(" + longLength + ").join('a'));\n" +
+            "/*\nException: " + shortedString + "\n*/",
+    label: "Correct exception message for a longString is shown"
+  });
+
+  runAsyncTests(scratchpad, tests).then(function() {
+    finish();
+  });
+}