diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/debug/Environment-variables.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/debug/Environment-variables.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,92 @@
+// Comprehensive test of get/setVariable on many kinds of environments and
+// bindings.
+
+load(libdir + "asserts.js");
+
+var cases = [
+    // global bindings and bindings on the global prototype chain
+    "x = VAL; @@",
+    "var x = VAL; @@",
+    "Object.prototype.x = VAL; @@",
+
+    // let, catch, and comprehension bindings
+    "let x = VAL; @@",
+    "{ let x = VAL; @@ }",
+    "let (x = VAL) { @@ }",
+    "try { throw VAL; } catch (x) { @@ }",
+    "try { throw VAL; } catch (x) { @@ }",
+    "for (let x of [VAL]) { @@ }",
+    "for each (let x in [VAL]) { @@ }",
+    "switch (0) { default: let x = VAL; @@ }",
+    "[function () { @@ }() for (x of [VAL])];",
+    // "((function () { @@ })() for (x of [VAL])).next();",  // bug 709367
+
+    // arguments
+    "function f(x) { @@ } f(VAL);",
+    "function f([w, x]) { @@ } f([0, VAL]);",
+    "function f({v: x}) { @@ } f({v: VAL});",
+    "function f([w, {v: x}]) { @@ } f([0, {v: VAL}]);",
+
+    // bindings in functions
+    "function f() { var x = VAL; @@ } f();",
+    "function f() { let x = VAL; @@ } f();",
+    "function f([x]) { let x = VAL; @@ } f(['fail']);",
+    "function f(x) { { let x = VAL; @@ } } f('fail');",
+    "function f() { function x() {} x = VAL; @@ } f();",
+
+    // dynamic bindings
+    "function f(s) { eval(s); @@ } f('var x = VAL');",
+    "function f(s) { let (x = 'fail') { eval(s); } x = VAL; @@ } f('var x;');",
+    "var x = VAL; function f(s) { eval('var x = 0;'); eval(s); @@ } f('delete x;');",
+    "function f(obj) { with (obj) { @@ } } f({x: VAL});",
+    "function f(obj) { with (obj) { @@ } } f(Object.create({x: VAL}));",
+    "function f(b) { if (b) { function x(){} } x = VAL; @@ } f(1);",
+];
+
+var nextval = 1000;
+
+function test(code, debugStmts, followupStmts) {
+    var val = nextval++;
+    var hits = 0;
+
+    var g = newGlobal();
+    g.eval("function debugMe() { var x = 'wrong-x'; debugger; }");
+    g.capture = null;
+
+    var dbg = Debugger(g);
+    dbg.onDebuggerStatement = function (frame) {
+        if (frame.callee !== null && frame.callee.name == 'debugMe')
+            frame = frame.older;
+        var env = frame.environment.find("x");
+        assertEq(env.getVariable("x"), val)
+        assertEq(env.setVariable("x", 'ok'), undefined);
+        assertEq(env.getVariable("x"), 'ok');
+
+        // setVariable cannot create new variables.
+        assertThrowsInstanceOf(function () { env.setVariable("newVar", 0); }, TypeError);
+        hits++;
+    };
+
+    code = code.replace("@@", debugStmts);
+    if (followupStmts !== undefined)
+        code += " " + followupStmts;
+    code = code.replace(/VAL/g, uneval(val));
+    g.eval(code);
+    assertEq(hits, 1);
+}
+
+for (var s of cases) {
+    // Test triggering the debugger right in the scope in which x is bound.
+    test(s, "debugger; assertEq(x, 'ok');");
+
+    // Test calling a function that triggers the debugger.
+    test(s, "debugMe(); assertEq(x, 'ok');");
+
+    // Test triggering the debugger from a scope nested in x's scope.
+    test(s, "let (y = 'irrelevant') { (function (z) { let (zz = y) { debugger; }})(); } assertEq(x, 'ok');"),
+
+    // Test closing over the variable and triggering the debugger later, after
+    // leaving the variable's scope.
+    test(s, "capture = {dbg: function () { debugger; }, get x() { return x; }};",
+            "assertEq(capture.x, VAL); capture.dbg(); assertEq(capture.x, 'ok');");
+}