diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/debug/Frame-environment-01.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/debug/Frame-environment-01.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,13 @@
+// frame.environment is a Debugger.Environment object
+
+var g = newGlobal()
+var dbg = Debugger(g);
+g.h = function () {
+    assertEq(dbg.getNewestFrame().environment instanceof Debugger.Environment, true);
+};
+
+g.eval("h()");
+g.evaluate("h()");
+g.eval("eval('h()')");
+g.eval("function f() { h(); }");
+g.f();