src/third_party/mozjs-45/js/src/jit-test/tests/basic/weird-scopechains.js

function checkNameLookup() {
    return "global";
}

function assertWithMessage(got, expected, message) {
    assertEq(message + ": " + got, message + ": " + expected);
}

function testFunc() {
    assertWithMessage(checkNameLookup(), "local", "nameLookup");
    assertWithMessage(checkThisBinding(), "local", "thisBinding");

    // Important: lambda needs to close over "reason", so it won't just get the
    // scope of testFunc as its scope.  Instead it'll get the Call object
    // "reason" lives in.
    var reason = " in lambda in Call";
    (function() {
	assertWithMessage(checkNameLookup(), "local", "nameLookup" + reason);
	assertWithMessage(checkThisBinding(), "local", "thisBinding" + reason);
    })();
}

var obj = {
    checkNameLookup: function() {
	return "local";
    },

    checkThisBinding: function() {
	return this.checkNameLookup();
    },
};

var cloneFunc = clone(testFunc, obj);
cloneFunc();