tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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for-in-with-assignment-semantics.js (1325B)

      1 /* This Source Code Form is subject to the terms of the Mozilla Public
      2 * License, v. 2.0. If a copy of the MPL was not distributed with this
      3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      4 
      5 const unreachable = () => { throw "unreachable"; };
      6 
      7 // var-initializer expression is executed before for-in expression.
      8 var log = "";
      9 for (var x = (log += "head") in (log += "|expr", null)) unreachable();
     10 assertEq(log, "head|expr");
     11 
     12 log = "";
     13 for (var x = (log += "head") in (log += "|expr", {})) unreachable();
     14 assertEq(log, "head|expr");
     15 
     16 
     17 // for-in expression isn't executed when var-initializer throws exception.
     18 function ExpectedError() {}
     19 assertThrowsInstanceOf(() => {
     20    var throwErr = () => { throw new ExpectedError(); };
     21    for (var x = throwErr() in unreachable()) unreachable();
     22 }, ExpectedError);
     23 
     24 
     25 // Ensure environment operations are performed correctly.
     26 var scope = new Proxy({x: 0}, new Proxy({}, {
     27    get(t, pk, r) {
     28        log += pk + "|";
     29    }
     30 }));
     31 
     32 log = "";
     33 with (scope) {
     34    for (var x = 0 in {}) ;
     35 }
     36 assertEq(log, "has|get|set|getOwnPropertyDescriptor|defineProperty|");
     37 
     38 log = "";
     39 with (scope) {
     40    for (var x = 0 in {p: 0}) ;
     41 }
     42 assertEq(log, "has|get|set|getOwnPropertyDescriptor|defineProperty|".repeat(2));
     43 
     44 
     45 if (typeof reportCompare === "function")
     46    reportCompare(true, true);