lexical-this.js (1347B)
1 // Copyright (C) 2015 the V8 project authors. All rights reserved. 2 // This code is governed by the BSD license found in the LICENSE file. 3 /*--- 4 es6id: 14.2.16 5 description: > 6 Runtime Semantics: Evaluation 7 8 this 9 10 ... 11 4. Let closure be FunctionCreate(Arrow, parameters, ConciseBody, scope, strict). 12 ... 13 14 The non-normative note elaborates on the "scope" argument: 15 16 An ArrowFunction does not define local bindings for arguments, super, this, or new.target. Any reference to arguments, super, or this within an ArrowFunction must resolve to a binding in a lexically enclosing environment. Typically this will be the Function Environment of an immediately enclosing function. Even though an ArrowFunction may contain references to super, the function object created in step 4 is not made into a method by performing MakeMethod. An ArrowFunction that references super is always contained within a non-ArrowFunction and the necessary state to implement super is accessible via the scope that is captured by the function object of the ArrowFunction. 17 ---*/ 18 19 function F() { 20 this.af = _ => { 21 return this; 22 }; 23 } 24 25 var usurper = {}; 26 var f = new F(); 27 28 assert.sameValue(f.af(), f); 29 assert.sameValue(f.af.apply(usurper), f); 30 assert.sameValue(f.af.call(usurper), f); 31 assert.sameValue(f.af.bind(usurper)(), f); 32 33 reportCompare(0, 0);