test_xpcwn_instanceof.js (1133B)
1 /* This Source Code Form is subject to the terms of the Mozilla Public 2 * License, v. 2.0. If a copy of the MPL was not distributed with this 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 4 5 // Tests for custom `instanceof` behavior via XPC_SCRIPTABLE_WANT_HASINSTANCE. 6 7 add_task(function id_instanceof() { 8 // ID objects are instances of Components.ID. 9 let id = Components.ID("{f2f5c784-7f6c-43f5-81b0-45ff32c312b1}"); 10 Assert.equal(id instanceof Components.ID, true); 11 Assert.equal({} instanceof Components.ID, false); 12 Assert.equal(null instanceof Components.ID, false); 13 14 // Components.ID has a Symbol.hasInstance function. 15 let desc = Object.getOwnPropertyDescriptor(Components.ID, Symbol.hasInstance); 16 Assert.equal(typeof desc, "object"); 17 Assert.equal(typeof desc.value, "function"); 18 19 // Test error handling when calling this function with unexpected values. 20 Assert.throws(() => desc.value.call(null), /At least 1 argument required/); 21 Assert.throws(() => desc.value.call(null, 1), /unexpected this value/); 22 Assert.throws(() => desc.value.call({}, {}), /NS_ERROR_XPC_BAD_OP_ON_WN_PROTO/); 23 });