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/* Any copyright is dedicated to the Public Domain.
http://creativecommons.org/publicdomain/zero/1.0/ */
"use strict";
// Test DevToolsUtils.defineLazyPrototypeGetter
function Class() {}
DevToolsUtils.defineLazyPrototypeGetter(Class.prototype, "foo", () => []);
function run_test() {
test_prototype_attributes();
test_instance_attributes();
test_multiple_instances();
test_callback_receiver();
}
function test_prototype_attributes() {
// Check that the prototype has a getter property with expected attributes.
const descriptor = Object.getOwnPropertyDescriptor(Class.prototype, "foo");
Assert.equal(typeof descriptor.get, "function");
Assert.equal(descriptor.set, undefined);
Assert.equal(descriptor.enumerable, false);
Assert.equal(descriptor.configurable, true);
}
function test_instance_attributes() {
// Instances should not have an own property until the lazy getter has been
// activated.
const instance = new Class();
Assert.ok(!instance.hasOwnProperty("foo"));
instance.foo;
Assert.ok(instance.hasOwnProperty("foo"));
// Check that the instance has an own property with the expecred value and
// attributes after the lazy getter is activated.
const descriptor = Object.getOwnPropertyDescriptor(instance, "foo");
Assert.ok(descriptor.value instanceof Array);
Assert.equal(descriptor.writable, true);
Assert.equal(descriptor.enumerable, false);
Assert.equal(descriptor.configurable, true);
}
function test_multiple_instances() {
const instance1 = new Class();
const instance2 = new Class();
const foo1 = instance1.foo;
const foo2 = instance2.foo;
// Check that the lazy getter returns the expected type of value.
Assert.ok(foo1 instanceof Array);
Assert.ok(foo2 instanceof Array);
// Make sure the lazy getter runs once and only once per instance.
Assert.equal(instance1.foo, foo1);
Assert.equal(instance2.foo, foo2);
// Make sure each instance gets its own unique value.
Assert.notEqual(foo1, foo2);
}
function test_callback_receiver() {
function Foo() {}
DevToolsUtils.defineLazyPrototypeGetter(Foo.prototype, "foo", function () {
return this;
});
// Check that the |this| value in the callback is the instance itself.
const instance = new Foo();
Assert.equal(instance.foo, instance);
}
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