src/third_party/mozjs-45/js/src/jit-test/tests/debug/Environment-identity-04.js

// Observably different visits to the same with-statement produce distinct Environments.

var g = newGlobal();
g.eval("function f(a, obj) { with (obj) return function () { return a; }; }");
var dbg = Debugger(g);
var hits = 0;
dbg.onDebuggerStatement = function (frame) {
    // Even though the two visits to the with-statement have the same target
    // object, Math, the environments are observably different.
    var f1 = frame.eval("f(1, Math);").return;
    var f2 = frame.eval("f(2, Math);").return;
    assertEq(f1.environment !== f2.environment, true);
    assertEq(f1.object, f2.object);
    assertEq(f1.call().return, 1);
    assertEq(f2.call().return, 2);
    hits++;
};
g.eval("debugger;");
assertEq(hits, 1);