// Copyright 2016 Microsoft, Inc. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- author: Brian Terlson esid: sec-async-function-instances description: > Async function instances are not constructors and do not have a [[Construct]] slot. info: | 25.5.1.1 AsyncFunction( p1, p2, … , pn, body ) ... 3. Return CreateDynamicFunction(C, NewTarget, "async", args). 19.2.1.1.1 Runtime Semantics: CreateDynamicFunction( constructor, newTarget, kind, args ) ... 33. Perform FunctionInitialize(F, Normal, parameters, body, scope). 34. If kind is "generator", then ... 35. Else if kind is "normal", perform MakeConstructor(F). 36. NOTE: Async functions are not constructable and do not have a [[Construct]] internal method or a "prototype" property. ... ---*/ async function foo() {} assert.throws(TypeError, function() { new foo(); }); var AsyncFunction = Object.getPrototypeOf(foo).constructor; var instance = AsyncFunction(); assert.throws(TypeError, function() { new instance(); })