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      1 // Copyright 2015 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // Flags: --allow-natives-syntax
      6 
      7 (function TestBasics() {
      8   var a = [1, 2];
      9   var b = [...a];
     10   assertArrayEquals([1, 2], b)
     11 
     12   assertArrayEquals(['a', 'b', 'c', 'd', 'e', 'f'],
     13                     ['a', ...'bc', 'd', ...'ef'])
     14 })();
     15 
     16 
     17 var log = [];
     18 
     19 function* gen(n) {
     20   log.push(n, 1);
     21   yield 1;
     22   log.push(n, 2);
     23   yield 2;
     24   log.push(n, 3);
     25   yield 3;
     26   log.push(n, 'done');
     27 }
     28 
     29 function id(v) {
     30   log.push(v);
     31   return v;
     32 }
     33 
     34 
     35 (function TestGenerator() {
     36   assertArrayEquals([1, 2, 3], [...gen('a')]);
     37   assertArrayEquals(['x', 1, 2, 3, 'y', 1, 2, 3, 'z'],
     38                     ['x', ...gen('a'), 'y', ...gen('b'), 'z']);
     39 })();
     40 
     41 
     42 (function TestOrderOfExecution() {
     43   log = [];
     44   assertArrayEquals(['x', 1, 2, 3, 'y', 1, 2, 3, 'z'],
     45                     [id('x'), ...gen('a'), id('y'), ...gen('b'), id('z')]);
     46   assertArrayEquals([
     47     'x', 'a', 1, 'a', 2, 'a', 3, 'a', 'done',
     48     'y', 'b', 1, 'b', 2, 'b', 3, 'b', 'done',
     49     'z'
     50   ], log);
     51 })();
     52 
     53 
     54 (function TestNotIterable() {
     55   var a;
     56   assertThrows(function() {
     57     a = [...42];
     58   }, TypeError);
     59   assertSame(undefined, a);
     60 
     61 
     62 })();
     63 
     64 
     65 (function TestInvalidIterator() {
     66   var iter = {
     67     [Symbol.iterator]: 42
     68   };
     69   var a;
     70   assertThrows(function() {
     71     a = [...iter];
     72   }, TypeError);
     73   assertSame(undefined, a);
     74 })();
     75 
     76 
     77 (function TestIteratorNotAnObject() {
     78   var iter = {
     79     [Symbol.iterator]() {
     80       return 42;
     81     }
     82   };
     83   var a;
     84   assertThrows(function() {
     85     a = [...iter];
     86   }, TypeError);
     87   assertSame(undefined, a);
     88 })();
     89 
     90 
     91 (function TestIteratorNoNext() {
     92   var iter = {
     93     [Symbol.iterator]() {
     94       return {};
     95     }
     96   };
     97   var a;
     98   assertThrows(function() {
     99     a = [...iter];
    100   }, TypeError);
    101   assertSame(undefined, a);
    102 })();
    103 
    104 
    105 (function TestIteratorResultDoneThrows() {
    106   function MyError() {}
    107   var iter = {
    108     [Symbol.iterator]() {
    109       return {
    110         next() {
    111           return {
    112             get done() {
    113               throw new MyError();
    114             }
    115           }
    116         }
    117       };
    118     }
    119   };
    120   var a;
    121   assertThrows(function() {
    122     a = [...iter];
    123   }, MyError);
    124   assertSame(undefined, a);
    125 })();
    126 
    127 
    128 (function TestIteratorResultValueThrows() {
    129   function MyError() {}
    130   var iter = {
    131     [Symbol.iterator]() {
    132       return {
    133         next() {
    134           return {
    135             done: false,
    136             get value() {
    137               throw new MyError();
    138             }
    139           }
    140         }
    141       };
    142     }
    143   };
    144   var a;
    145   assertThrows(function() {
    146     a = [...iter];
    147   }, MyError);
    148   assertSame(undefined, a);
    149 })();
    150 
    151 
    152 (function TestOptimize() {
    153   function f() {
    154     return [...'abc'];
    155   }
    156   assertArrayEquals(['a', 'b', 'c'], f());
    157   %OptimizeFunctionOnNextCall(f);
    158   assertArrayEquals(['a', 'b', 'c'], f());
    159 })();
    160 
    161 
    162 (function TestDeoptimize() {
    163   var iter = {
    164     [Symbol.iterator]() {
    165       var i = 0;
    166       return {
    167         next() {
    168           $DeoptimizeFunction(f);
    169           return {value: ++i, done: i === 3};
    170         }
    171       };
    172     }
    173   };
    174   function f() {
    175     return [0, ...iter];
    176   }
    177 
    178   assertArrayEquals([0, 1, 2], f());
    179 });
    180