var BUGNUMBER = 1185106; var summary = "async/await syntax"; print(BUGNUMBER + ": " + summary); if (typeof Reflect !== "undefined" && Reflect.parse) { assertEq(Reflect.parse("function a() {}").body[0].async, false); assertEq(Reflect.parse("function* a() {}").body[0].async, false); assertEq(Reflect.parse("async function a() {}").body[0].async, true); assertEq(Reflect.parse("() => {}").body[0].async, undefined); // No line terminator after async assertEq(Reflect.parse("async\nfunction a(){}").body[0].expression.name, "async"); // Async function expressions assertEq(Reflect.parse("(async function() {})()").body[0].expression.callee.async, true); assertEq(Reflect.parse("var k = async function() {}").body[0].declarations[0].init.async, true); assertEq(Reflect.parse("var nmd = async function named() {}").body[0].declarations[0].init.id.name, "named"); // `await` handling for function declaration name inherits. assertEq(Reflect.parse("async function await() {}").body[0].id.name, "await"); assertThrows(() => Reflect.parse("async function f() { async function await() {} }"), SyntaxError); // `await` is not allowed in function expression name. assertThrows(() => Reflect.parse("(async function await() {})"), SyntaxError); // Awaiting not directly inside an async function is not allowed assertThrows(() => Reflect.parse("await 4;"), SyntaxError); assertThrows(() => Reflect.parse("function a() { await 4; }"), SyntaxError); assertThrows(() => Reflect.parse("function* a() { await 4; }"), SyntaxError); assertThrows(() => Reflect.parse("async function k() { function a() { await 4; } }"), SyntaxError); // Await is not allowed as a default expr. assertThrows(() => Reflect.parse("async function a(k = await 3) {}"), SyntaxError); assertThrows(() => Reflect.parse("async function a() { async function b(k = await 3) {} }"), SyntaxError); assertThrows(() => Reflect.parse("async function a() { async function b(k = [await 3]) {} }"), SyntaxError); assertThrows(() => Reflect.parse("async function a() { async function b([k = await 3]) {} }"), SyntaxError); assertThrows(() => Reflect.parse("async function a() { async function b([k = [await 3]]) {} }"), SyntaxError); assertThrows(() => Reflect.parse("async function a() { async function b({k = await 3}) {} }"), SyntaxError); assertThrows(() => Reflect.parse("async function a() { async function b({k = [await 3]}) {} }"), SyntaxError); // Await is not legal as an identifier in an async function. assertThrows(() => Reflect.parse("async function a() { var await = 4; }"), SyntaxError); assertThrows(() => Reflect.parse("async function a() { return await; }"), SyntaxError); // Await is still available as an identifier name in strict mode code. Reflect.parse("function a() { 'use strict'; var await = 3; }"); Reflect.parse("'use strict'; var await = 3;"); // Await is treated differently depending on context. Various cases. Reflect.parse("var await = 3; async function a() { await 4; }"); Reflect.parse("async function a() { await 4; } var await = 5"); Reflect.parse("async function a() { function b() { return await; } }"); Reflect.parse("async function a() { var k = { async: 4 } }"); Reflect.parse("function a() { await: 4 }"); assertEq(Reflect.parse("async function a() { await 4; }") .body[0].body.body[0].expression.operator, "await"); assertEq(Reflect.parse("async function a() { async function b() { await 4; } }") .body[0].body.body[0].body.body[0].expression.operator, "await"); // operator priority test assertEq(Reflect.parse("async function a() { await 2 + 3; }") .body[0].body.body[0].expression.left.argument.value, 2); assertEq(Reflect.parse("async function a() { await 2 + 3; }") .body[0].body.body[0].expression.left.operator, "await"); assertEq(Reflect.parse("async function a() { await 2 + 3; }") .body[0].body.body[0].expression.right.value, 3); // blocks and other constructions assertEq(Reflect.parse("{ async function a() { return 2; } }") .body[0].body[0].async, true); // Async function expression is primary expression. Reflect.parse("(async function a() {}.constructor)"); } if (typeof reportCompare === "function") reportCompare(true, true);