binding-not-blocked-by-unscopables-falsey-prop.js (1525B)
1 // Copyright 2015 Mike Pennisi. All rights reserved. 2 // This code is governed by the BSD license found in the LICENSE file. 3 4 /*--- 5 es6id: 8.1.1.2.1 6 description: > 7 False-coercing `Symbol.unscopables` properties do not block access to object environment record 8 info: | 9 [...] 10 6. If the withEnvironment flag of envRec is false, return true. 11 7. Let unscopables be Get(bindings, @@unscopables). 12 8. ReturnIfAbrupt(unscopables). 13 9. If Type(unscopables) is Object, then 14 a. Let blocked be ToBoolean(Get(unscopables, N)). 15 b. ReturnIfAbrupt(blocked). 16 c. If blocked is true, return false. 17 10. Return true. 18 19 ES6: 13.11.7 (The `with` Statement) Runtime Semantics: Evaluation 20 [...] 21 6. Set the withEnvironment flag of newEnv’s EnvironmentRecord to true. 22 [...] 23 flags: [noStrict] 24 features: [Symbol.unscopables] 25 ---*/ 26 27 var x = 0; 28 var env = { x: 1 }; 29 env[Symbol.unscopables] = {}; 30 31 with (env) { 32 assert.sameValue(x, 1, 'undefined (no property defined)'); 33 } 34 35 env[Symbol.unscopables].x = false; 36 with (env) { 37 assert.sameValue(x, 1, 'literal `false` value'); 38 } 39 40 env[Symbol.unscopables].x = undefined; 41 with (env) { 42 assert.sameValue(x, 1, 'literal `undefined` value'); 43 } 44 45 env[Symbol.unscopables].x = null; 46 with (env) { 47 assert.sameValue(x, 1, 'null value'); 48 } 49 50 env[Symbol.unscopables].x = 0; 51 with (env) { 52 assert.sameValue(x, 1, 'literal `0` number value'); 53 } 54 55 env[Symbol.unscopables].x = ''; 56 with (env) { 57 assert.sameValue(x, 1, 'empty string value'); 58 } 59 60 reportCompare(0, 0);