"use strict"; var {ObjectUtils} = Components.utils.import("resource://gre/modules/ObjectUtils.jsm", {}); var {Promise} = Components.utils.import("resource://gre/modules/Promise.jsm", {}); add_task(function* init() { // The code will cause uncaught rejections on purpose. Promise.Debugging.clearUncaughtErrorObservers(); }); add_task(function* test_strict() { let loose = { a: 1 }; let strict = ObjectUtils.strict(loose); loose.a; // Should not throw. loose.b || undefined; // Should not throw. strict.a; // Should not throw. Assert.throws(() => strict.b, /No such property: "b"/); "b" in strict; // Should not throw. strict.b = 2; strict.b; // Should not throw. Assert.throws(() => strict.c, /No such property: "c"/); "c" in strict; // Should not throw. loose.c = 3; strict.c; // Should not throw. }); function run_test() { run_next_test(); }