diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_parser-01.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_parser-01.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,31 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Check that simple JS can be parsed and cached with the reflection API.
+ */
+
+function test() {
+  let { Parser } = Cu.import("resource:///modules/devtools/Parser.jsm", {});
+
+  let source = "let x = 42;";
+  let parser = new Parser();
+  let first = parser.get(source);
+  let second = parser.get(source);
+
+  isnot(first, second,
+    "The two syntax trees should be different.");
+
+  let third = parser.get(source, "url");
+  let fourth = parser.get(source, "url");
+
+  isnot(first, third,
+    "The new syntax trees should be different than the old ones.");
+  is(third, fourth,
+    "The new syntax trees were cached once an identifier was specified.");
+
+  is(parser.errors.length, 0,
+    "There should be no errors logged when parsing.");
+
+  finish();
+}