tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

lgcl-nullish-assignment-operator.js (1919B)

      1 // Copyright (c) 2020 Ecma International.  All rights reserved.
      2 // This code is governed by the BSD license found in the LICENSE file.
      3 
      4 /*---
      5 esid: sec-assignment-operators-runtime-semantics-evaluation
      6 description: Logical Nullish Assignment Operator
      7 info: |
      8    AssignmentExpression:
      9      LeftHandSideExpression ??= AssignmentExpression
     10 
     11    1. Let lref be the result of evaluating LeftHandSideExpression.
     12    2. Let lval be ? GetValue(lref).
     13    3. If lval is neither undefined nor null, return lval.
     14    4. Let rref be the result of evaluating AssignmentExpression.
     15    5. Let rval be ? GetValue(rref).
     16    6. Perform ? PutValue(lref, rval).
     17    7. Return rval.
     18 features: [logical-assignment-operators]
     19 
     20 ---*/
     21 
     22 var value = undefined;
     23 assert.sameValue(value ??= 1, 1, "(value ??= 1) === 1; where value = undefined");
     24 
     25 value = null;
     26 assert.sameValue(value ??= 1, 1, "(value ??= 1) === 1; where value = null");
     27 
     28 value = false;
     29 assert.sameValue(value ??= 1, false, "(value ??= 1) === false; where value = false");
     30 
     31 value = 0;
     32 assert.sameValue(value ??= 1, 0, "(value ??= 1) === 0; where value = 0");
     33 
     34 value = -0;
     35 assert.sameValue(value ??= 1, -0, "(value ??= 1) === -0; where value = -0");
     36 
     37 value = NaN;
     38 assert.sameValue(value ??= 1, NaN, "(value ??= 1) === NaN; where value = NaN");
     39 
     40 value = "";
     41 assert.sameValue(value ??= 1, "", '(value ??= 1) === "" where value = ""');
     42 
     43 
     44 
     45 value = true;
     46 assert.sameValue(value ??= 1, true, "(value ??= 1) === true; where value = true");
     47 
     48 value = 2;
     49 assert.sameValue(value ??= 1, 2, "(value ??= 1) === 2; where value = 2");
     50 
     51 value = "test";
     52 assert.sameValue(value ??= 1, "test", '(value ??= 1) === "test"; where value = "test"');
     53 
     54 var sym = Symbol("");
     55 value = sym;
     56 assert.sameValue(value ??= 1, sym, "(value ??= 1) === Symbol(); where value = Symbol()");
     57 
     58 var obj = {};
     59 value = obj;
     60 assert.sameValue(value ??= 1, obj, "(value ??= 1) === {}; where value = {}");
     61 
     62 reportCompare(0, 0);