destructuring.js 31.1 KB
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// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

(function TestObjectLiteralPattern() {
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  var { x : x, y : y, get, set } = { x : 1, y : 2, get: 3, set: 4 };
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  assertEquals(1, x);
  assertEquals(2, y);
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  assertEquals(3, get);
  assertEquals(4, set);
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  var {z} = { z : 3 };
  assertEquals(3, z);
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  var sum = 0;
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  for (var {z} = { z : 3 }; z != 0; z--) {
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    sum += z;
  }
  assertEquals(6, sum);
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  var log = [];
  var o = {
    get x() {
      log.push("x");
      return 0;
    },
    get y() {
      log.push("y");
      return {
        get z() { log.push("z"); return 1; }
      }
    }
  };
  var { x : x0, y : { z : z1 }, x : x1 } = o;
  assertSame(0, x0);
  assertSame(1, z1);
  assertSame(0, x1);
  assertArrayEquals(["x", "y", "z", "x"], log);
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}());


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(function TestObjectLiteralPatternInitializers() {
  var { x : x, y : y = 2 } = { x : 1 };
  assertEquals(1, x);
  assertEquals(2, y);

  var {z = 3} = {};
  assertEquals(3, z);

  var sum = 0;
  for (var {z = 3} = {}; z != 0; z--) {
    sum += z;
  }
  assertEquals(6, sum);

  var log = [];
  var o = {
    get x() {
      log.push("x");
      return undefined;
    },
    get y() {
      log.push("y");
      return {
        get z() { log.push("z"); return undefined; }
      }
    }
  };
  var { x : x0 = 0, y : { z : z1 = 1}, x : x1 = 0} = o;
  assertSame(0, x0);
  assertSame(1, z1);
  assertSame(0, x1);
  assertArrayEquals(["x", "y", "z", "x"], log);
}());


(function TestObjectLiteralPatternLexicalInitializers() {
  'use strict';
  let { x : x, y : y = 2 } = { x : 1 };
  assertEquals(1, x);
  assertEquals(2, y);

  let {z = 3} = {};
  assertEquals(3, z);

  let log = [];
  let o = {
    get x() {
      log.push("x");
      return undefined;
    },
    get y() {
      log.push("y");
      return {
        get z() { log.push("z"); return undefined; }
      }
    }
  };

  let { x : x0 = 0, y : { z : z1 = 1 }, x : x1 = 5} = o;
  assertSame(0, x0);
  assertSame(1, z1);
  assertSame(5, x1);
  assertArrayEquals(["x", "y", "z", "x"], log);

  let sum = 0;
  for (let {x = 0, z = 3} = {}; z != 0; z--) {
    assertEquals(0, x);
    sum += z;
  }
  assertEquals(6, sum);
}());


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(function TestObjectLiteralPatternLexical() {
  'use strict';
  let { x : x, y : y } = { x : 1, y : 2 };
  assertEquals(1, x);
  assertEquals(2, y);

  let {z} = { z : 3 };
  assertEquals(3, z);

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  let log = [];
  let o = {
    get x() {
      log.push("x");
      return 0;
    },
    get y() {
      log.push("y");
      return {
        get z() { log.push("z"); return 1; }
      }
    }
  };
  let { x : x0, y : { z : z1 }, x : x1 } = o;
  assertSame(0, x0);
  assertSame(1, z1);
  assertSame(0, x1);
  assertArrayEquals(["x", "y", "z", "x"], log);
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  let sum = 0;
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  for (let {x, z} = { x : 0, z : 3 }; z != 0; z--) {
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    assertEquals(0, x);
    sum += z;
  }
  assertEquals(6, sum);
}());


(function TestObjectLiteralPatternLexicalConst() {
  'use strict';
  const { x : x, y : y } = { x : 1, y : 2 };
  assertEquals(1, x);
  assertEquals(2, y);

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  assertThrows(function() { x++; }, TypeError);
  assertThrows(function() { y++; }, TypeError);

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  const {z} = { z : 3 };
  assertEquals(3, z);

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  for (const {x, z} = { x : 0, z : 3 }; z != 3 || x != 0;) {
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    assertTrue(false);
  }
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}());
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(function TestFailingMatchesSloppy() {
  var {x, y} = {};
  assertSame(undefined, x);
  assertSame(undefined, y);

  var { x : { z1 }, y2} = { x : {}, y2 : 42 }
  assertSame(undefined, z1);
  assertSame(42, y2);
}());


(function TestFailingMatchesStrict() {
  'use strict';
  var {x, y} = {};
  assertSame(undefined, x);
  assertSame(undefined, y);

  var { x : { z1 }, y2} = { x : {}, y2 : 42 }
  assertSame(undefined, z1);
  assertSame(42, y2);

  {
    let {x1,y1} = {};
    assertSame(undefined, x1);
    assertSame(undefined, y1);

    let { x : { z1 }, y2} = { x : {}, y2 : 42 }
    assertSame(undefined, z1);
    assertSame(42, y2);
  }
}());


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(function TestTDZInIntializers() {
  'use strict';
  {
    let {x, y = x} = {x : 42, y : 27};
    assertSame(42, x);
    assertSame(27, y);
  }

  {
    let {x, y = x + 1} = { x : 42 };
    assertSame(42, x);
    assertSame(43, y);
  }
  assertThrows(function() {
    let {x = y, y} = { y : 42 };
  }, ReferenceError);

  {
    let {x, y = eval("x+1")} = {x:42};
    assertEquals(42, x);
    assertEquals(43, y);
  }

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  {
    let {x, y = () => eval("x+1")} = {x:42};
    assertEquals(42, x);
    assertEquals(43, y());
  }

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  {
    let {x = function() {return y+1;}, y} = {y:42};
    assertEquals(43, x());
    assertEquals(42, y);
  }
  {
    let {x = function() {return eval("y+1");}, y} = {y:42};
    assertEquals(43, x());
    assertEquals(42, y);
  }
}());


(function TestSideEffectsInInitializers() {
  var callCount = 0;
  function f(v) { callCount++; return v; }

  callCount = 0;
  var { x = f(42) } = { x : 27 };
  assertSame(27, x);
  assertEquals(0, callCount);

  callCount = 0;
  var { x = f(42) } = {};
  assertSame(42, x);
  assertEquals(1, callCount);
}());


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(function TestAssignmentExprInInitializers() {
  {
    let x, y;
    {
      let { x = y = 1 } = {};
      assertSame(x, 1);
      assertSame(y, 1);
    }
    assertSame(undefined, x);
    assertSame(1, y);
  }

  {
    let x, y;
    {
      let { x: x = y = 1 } = {};
      assertSame(1, x);
      assertSame(1, y);
    }
    assertSame(undefined, x);
    assertSame(1, y);
  }

  {
    let x, y;
    {
      let [ x = y = 1 ] = [];
      assertSame(1, x);
      assertSame(1, y);
    }
    assertSame(undefined, x);
    assertSame(1, y);
  }

  {
    let x, y;
    (function({ x = y = 1 }) {}({}));
    assertSame(undefined, x);
    assertSame(1, y);
  }

  {
    let x, y;
    (function({ x: x = y = 1 }) {}({}));
    assertSame(undefined, x);
    assertSame(1, y);
  }

  {
    let x, y;
    (function([ x = y = 1 ]) {}([]));
    assertSame(undefined, x);
    assertSame(1, y);
  }
}());


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(function TestMultipleAccesses() {
  assertThrows(
    "'use strict';"+
    "const {x,x} = {x:1};",
    SyntaxError);

  assertThrows(
    "'use strict';"+
    "let {x,x} = {x:1};",
     SyntaxError);

  (function() {
    var {x,x = 2} = {x : 1};
    assertSame(1, x);
  }());

  assertThrows(function () {
    'use strict';
    let {x = (function() { x = 2; }())} = {};
  }, ReferenceError);

  (function() {
    'use strict';
    let {x = (function() { x = 2; }())} = {x:1};
    assertSame(1, x);
  }());
}());


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(function TestComputedNames() {
  var x = 1;
  var {[x]:y} = {1:2};
  assertSame(2, y);

  (function(){
    'use strict';
    let {[x]:y} = {1:2};
    assertSame(2, y);
  }());

  var callCount = 0;
  function foo(v) { callCount++; return v; }

  (function() {
    callCount = 0;
    var {[foo("abc")]:x} = {abc:42};
    assertSame(42, x);
    assertEquals(1, callCount);
  }());

  (function() {
    'use strict';
    callCount = 0;
    let {[foo("abc")]:x} = {abc:42};
    assertSame(42, x);
    assertEquals(1, callCount);
  }());

  (function() {
    callCount = 0;
    var {[foo("abc")]:x} = {};
    assertSame(undefined, x);
    assertEquals(1, callCount);
  }());

  (function() {
    'use strict';
    callCount = 0;
    let {[foo("abc")]:x} = {};
    assertSame(undefined, x);
    assertEquals(1, callCount);
  }());

  for (val of [null, undefined]) {
    callCount = 0;
    assertThrows(function() {
      var {[foo()]:x} = val;
    }, TypeError);
    assertEquals(0, callCount);

    callCount = 0;
    assertThrows(function() {
      'use strict';
      let {[foo()]:x} = val;
    }, TypeError);
    assertEquals(0, callCount);
  }

  var log = [];
  var o = {
    get x() { log.push("get x"); return 1; },
    get y() { log.push("get y"); return 2; }
  }
  function f(v) { log.push("f " + v); return v; }

  (function() {
    log = [];
    var { [f('x')]:x, [f('y')]:y } = o;
    assertSame(1, x);
    assertSame(2, y);
    assertArrayEquals(["f x", "get x", "f y", "get y"], log);
  }());

  (function() {
    'use strict';
    log = [];
    let { [f('x')]:x, [f('y')]:y } = o;
    assertSame(1, x);
    assertSame(2, y);
    assertArrayEquals(["f x", "get x", "f y", "get y"], log);
  }());

  (function() {
    'use strict';
    log = [];
    const { [f('x')]:x, [f('y')]:y } = o;
    assertSame(1, x);
    assertSame(2, y);
    assertArrayEquals(["f x", "get x", "f y", "get y"], log);
  }());
}());


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(function TestExceptions() {
  for (var val of [null, undefined]) {
    assertThrows(function() { var {} = val; }, TypeError);
    assertThrows(function() { var {x} = val; }, TypeError);
    assertThrows(function() { var { x : {} } = { x : val }; }, TypeError);
    assertThrows(function() { 'use strict'; let {} = val; }, TypeError);
    assertThrows(function() { 'use strict'; let {x} = val; }, TypeError);
    assertThrows(function() { 'use strict'; let { x : {} } = { x : val }; },
                 TypeError);
  }
}());
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(function TestArrayLiteral() {
  var [a, b, c] = [1, 2, 3];
  assertSame(1, a);
  assertSame(2, b);
  assertSame(3, c);
}());

(function TestIterators() {
  var log = [];
  function* f() {
    log.push("1");
    yield 1;
    log.push("2");
    yield 2;
    log.push("3");
    yield 3;
    log.push("done");
  };

  (function() {
    log = [];
    var [a, b, c] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertSame(3, c);
    assertArrayEquals(["1", "2", "3"], log);
  }());

  (function() {
    log = [];
    var [a, b, c, d] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertSame(3, c);
    assertSame(undefined, d);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());

  (function() {
    log = [];
    var [a, , c] = f();
    assertSame(1, a);
    assertSame(3, c);
    assertArrayEquals(["1", "2", "3"], log);
  }());

  (function() {
    log = [];
    var [a, , c, d] = f();
    assertSame(1, a);
    assertSame(3, c);
    assertSame(undefined, d);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());

  (function() {
    log = [];
    // last comma is not an elision.
    var [a, b,] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertArrayEquals(["1", "2"], log);
  }());

  (function() {
    log = [];
    // last comma is not an elision, but the comma before the last is.
    var [a, b, ,] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertArrayEquals(["1", "2", "3"], log);
  }());

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  (function() {
    log = [];
    var [a, ...rest] = f();
    assertSame(1, a);
    assertArrayEquals([2,3], rest);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());

  (function() {
    log = [];
    var [a, b, c, ...rest] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertSame(3, c);
    assertArrayEquals([], rest);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());

  (function() {
    log = [];
    var [a, b, c, d, ...rest] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertSame(3, c);
    assertSame(undefined, d);
    assertArrayEquals([], rest);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());
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}());


(function TestIteratorsLexical() {
  'use strict';
  var log = [];
  function* f() {
    log.push("1");
    yield 1;
    log.push("2");
    yield 2;
    log.push("3");
    yield 3;
    log.push("done");
  };

  (function() {
    log = [];
    let [a, b, c] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertSame(3, c);
    assertArrayEquals(["1", "2", "3"], log);
  }());

  (function() {
    log = [];
    let [a, b, c, d] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertSame(3, c);
    assertSame(undefined, d);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());

  (function() {
    log = [];
    let [a, , c] = f();
    assertSame(1, a);
    assertSame(3, c);
    assertArrayEquals(["1", "2", "3"], log);
  }());

  (function() {
    log = [];
    let [a, , c, d] = f();
    assertSame(1, a);
    assertSame(3, c);
    assertSame(undefined, d);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());

  (function() {
    log = [];
    // last comma is not an elision.
    let [a, b,] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertArrayEquals(["1", "2"], log);
  }());

  (function() {
    log = [];
    // last comma is not an elision, but the comma before the last is.
    let [a, b, ,] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertArrayEquals(["1", "2", "3"], log);
  }());

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  (function() {
    log = [];
    let [a, ...rest] = f();
    assertSame(1, a);
    assertArrayEquals([2,3], rest);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());

  (function() {
    log = [];
    let [a, b, c, ...rest] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertSame(3, c);
    assertArrayEquals([], rest);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());

  (function() {
    log = [];
    let [a, b, c, d, ...rest] = f();
    assertSame(1, a);
    assertSame(2, b);
    assertSame(3, c);
    assertSame(undefined, d);
    assertArrayEquals([], rest);
    assertArrayEquals(["1", "2", "3", "done"], log);
  }());
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}());

(function TestIteratorsRecursive() {
  var log = [];
  function* f() {
    log.push("1");
    yield {x : 1, y : 2};
    log.push("2");
    yield [42, 27, 30];
    log.push("3");
    yield "abc";
    log.push("done");
  };

  (function() {
    var [{x, y}, [a, b]] = f();
    assertSame(1, x);
    assertSame(2, y);
    assertSame(42, a);
    assertSame(27, b);
    assertArrayEquals(["1", "2"], log);
  }());

  (function() {
    'use strict';
    log = [];
    let [{x, y}, [a, b]] = f();
    assertSame(1, x);
    assertSame(2, y);
    assertSame(42, a);
    assertSame(27, b);
    assertArrayEquals(["1", "2"], log);
  }());
}());
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(function TestForEachLexical() {
  'use strict';
  let a = [{x:1, y:-1}, {x:2,y:-2}, {x:3,y:-3}];
  let sumX = 0;
  let sumY = 0;
  let fs = [];
  for (let {x,y} of a) {
    sumX += x;
    sumY += y;
    fs.push({fx : function() { return x; }, fy : function() { return y }});
  }
  assertSame(6, sumX);
  assertSame(-6, sumY);
  assertSame(3, fs.length);
  for (let i = 0; i < fs.length; i++) {
    let {fx,fy} = fs[i];
    assertSame(i+1, fx());
    assertSame(-(i+1), fy());
  }

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  var o = { __proto__:null, 'a1':1, 'b2':2 };
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  let sx = '';
  let sy = '';
  for (let [x,y] in o) {
    sx += x;
    sy += y;
  }
  assertEquals('ab', sx);
  assertEquals('12', sy);
}());
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(function TestForEachVars() {
  var a = [{x:1, y:-1}, {x:2,y:-2}, {x:3,y:-3}];
  var sumX = 0;
  var sumY = 0;
  var fs = [];
  for (var {x,y} of a) {
    sumX += x;
    sumY += y;
    fs.push({fx : function() { return x; }, fy : function() { return y }});
  }
  assertSame(6, sumX);
  assertSame(-6, sumY);
  assertSame(3, fs.length);
  for (var i = 0; i < fs.length; i++) {
    var {fx,fy} = fs[i];
    assertSame(3, fx());
    assertSame(-3, fy());
  }

  var o = { __proto__:null, 'a1':1, 'b2':2 };
  var sx = '';
  var sy = '';
  for (var [x,y] in o) {
    sx += x;
    sy += y;
  }
  assertEquals('ab', sx);
  assertEquals('12', sy);
}());
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(function TestParameters() {
  function f({a, b}) { return a - b; }
  assertEquals(1, f({a : 6, b : 5}));

  function f1(c, {a, b}) { return c + a - b; }
  assertEquals(8, f1(7, {a : 6, b : 5}));

  function f2({c, d}, {a, b}) { return c - d + a - b; }
  assertEquals(7, f2({c : 7, d : 1}, {a : 6, b : 5}));

  function f3([{a, b}]) { return a - b; }
  assertEquals(1, f3([{a : 6, b : 5}]));

  var g = ({a, b}) => { return a - b; };
  assertEquals(1, g({a : 6, b : 5}));

  var g1 = (c, {a, b}) => { return c + a - b; };
  assertEquals(8, g1(7, {a : 6, b : 5}));

  var g2 = ({c, d}, {a, b}) => { return c - d + a - b; };
  assertEquals(7, g2({c : 7, d : 1}, {a : 6, b : 5}));

  var g3 = ([{a, b}]) => { return a - b; };
  assertEquals(1, g3([{a : 6, b : 5}]));
}());


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(function TestExpressionsInParameters() {
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  function f0(x = eval(0)) { return x }
  assertEquals(0, f0());
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  function f1({a = eval(1)}) { return a }
  assertEquals(1, f1({}));
  function f2([x = eval(2)]) { return x }
  assertEquals(2, f2([]));
  function f3({[eval(7)]: x}) { return x }
  assertEquals(3, f3({7: 3}));
})();


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(function TestParameterScoping() {
  var x = 1;

  function f1({a = x}) { var x = 2; return a; }
  assertEquals(1, f1({}));
  function f2({a = x}) { function x() {}; return a; }
  assertEquals(1, f2({}));
800 801 802 803 804 805 806 807 808
  (function() {
    'use strict';
    function f3({a = x}) { let x = 2; return a; }
    assertEquals(1, f3({}));
    function f4({a = x}) { const x = 2; return a; }
    assertEquals(1, f4({}));
    function f5({a = x}) { function x() {}; return a; }
    assertEquals(1, f5({}));
  })();
809 810
  function f6({a = eval("x")}) { var x; return a; }
  assertEquals(1, f6({}));
811 812 813 814 815
  (function() {
    'use strict';
    function f61({a = eval("x")}) { var x; return a; }
    assertEquals(1, f61({}));
  })();
816 817
  function f62({a = eval("'use strict'; x")}) { var x; return a; }
  assertEquals(1, f62({}));
818 819 820 821
  function f7({a = function() { return x }}) { var x; return a(); }
  assertEquals(1, f7({}));
  function f8({a = () => x}) { var x; return a(); }
  assertEquals(1, f8({}));
822 823
  function f9({a = () => eval("x")}) { var x; return a(); }
  assertEquals(1, f9({}));
824 825 826 827 828
  (function TestInitializedWithEvalArrowStrict() {
    'use strict';
    function f91({a = () => eval("x")}) { var x; return a(); }
    assertEquals(1, f91({}));
  })();
829 830 831 832
  function f92({a = () => { 'use strict'; return eval("x") }}) { var x; return a(); }
  assertEquals(1, f92({}));
  function f93({a = () => eval("'use strict'; x")}) { var x; return a(); }
  assertEquals(1, f93({}));
833 834 835 836 837

  var g1 = ({a = x}) => { var x = 2; return a; };
  assertEquals(1, g1({}));
  var g2 = ({a = x}) => { function x() {}; return a; };
  assertEquals(1, g2({}));
838 839 840 841 842 843 844 845 846
  (function() {
    'use strict';
    var g3 = ({a = x}) => { let x = 2; return a; };
    assertEquals(1, g3({}));
    var g4 = ({a = x}) => { const x = 2; return a; };
    assertEquals(1, g4({}));
    var g5 = ({a = x}) => { function x() {}; return a; };
    assertEquals(1, g5({}));
  })();
847 848
  var g6 = ({a = eval("x")}) => { var x; return a; };
  assertEquals(1, g6({}));
849 850 851 852 853
  (function() {
    'use strict';
    var g61 = ({a = eval("x")}) => { var x; return a; };
    assertEquals(1, g61({}));
  })();
854 855
  var g62 = ({a = eval("'use strict'; x")}) => { var x; return a; };
  assertEquals(1, g62({}));
856 857 858 859
  var g7 = ({a = function() { return x }}) => { var x; return a(); };
  assertEquals(1, g7({}));
  var g8 = ({a = () => x}) => { var x; return a(); };
  assertEquals(1, g8({}));
860 861
  var g9 = ({a = () => eval("x")}) => { var x; return a(); };
  assertEquals(1, g9({}));
862 863 864 865 866 867 868
  (function() {
    'use strict';
    var g91 = ({a = () => eval("x")}) => { var x; return a(); };
    assertEquals(1, g91({}));
    var g92 = ({a = () => { return eval("x") }}) => { var x; return a(); };
    assertEquals(1, g92({}));
  })();
869 870
  var g93 = ({a = () => eval("'use strict'; x")}) => { var x; return a(); };
  assertEquals(1, g93({}));
871 872 873 874 875

  var f11 = function f({x = f}) { var f; return x; }
  assertSame(f11, f11({}));
  var f12 = function f({x = f}) { function f() {}; return x; }
  assertSame(f12, f12({}));
876 877 878 879 880 881 882 883 884
  (function() {
    'use strict';
    var f13 = function f({x = f}) { let f; return x; }
    assertSame(f13, f13({}));
    var f14 = function f({x = f}) { const f = 0; return x; }
    assertSame(f14, f14({}));
    var f15 = function f({x = f}) { function f() {}; return x; }
    assertSame(f15, f15({}));
  })();
885 886
  var f16 = function f({f = 7, x = f}) { return x; }
  assertSame(7, f16({}));
887 888 889 890

  var y = 'a';
  function f20({[y]: x}) { var y = 'b'; return x; }
  assertEquals(1, f20({a: 1, b: 2}));
891 892
  function f21({[eval('y')]: x}) { var y = 'b'; return x; }
  assertEquals(1, f21({a: 1, b: 2}));
893 894
  var g20 = ({[y]: x}) => { var y = 'b'; return x; };
  assertEquals(1, g20({a: 1, b: 2}));
895 896
  var g21 = ({[eval('y')]: x}) => { var y = 'b'; return x; };
  assertEquals(1, g21({a: 1, b: 2}));
897 898 899
})();


900
(function TestParameterDestructuringTDZ() {
901 902 903
  function f1({a = x}, x) { return a }
  assertThrows(() => f1({}, 4), ReferenceError);
  assertEquals(4, f1({a: 4}, 5));
904 905 906
  function f2({a = eval("x")}, x) { return a }
  assertThrows(() => f2({}, 4), ReferenceError);
  assertEquals(4, f2({a: 4}, 5));
907 908 909 910 911 912
  (function() {
    'use strict';
    function f3({a = eval("x")}, x) { return a }
    assertThrows(() => f3({}, 4), ReferenceError);
    assertEquals(4, f3({a: 4}, 5));
  })();
913 914 915
  function f4({a = eval("'use strict'; x")}, x) { return a }
  assertThrows(() => f4({}, 4), ReferenceError);
  assertEquals(4, f4({a: 4}, 5));
916 917 918

  function f5({a = () => x}, x) { return a() }
  assertEquals(4, f5({a: () => 4}, 5));
919 920
  function f6({a = () => eval("x")}, x) { return a() }
  assertEquals(4, f6({a: () => 4}, 5));
921 922 923 924 925
  (function() {
    'use strict';
    function f7({a = () => eval("x")}, x) { return a() }
    assertEquals(4, f7({a: () => 4}, 5));
  })();
926 927
  function f8({a = () => eval("'use strict'; x")}, x) { return a() }
  assertEquals(4, f8({a: () => 4}, 5));
928 929 930 931

  function f11({a = b}, {b}) { return a }
  assertThrows(() => f11({}, {b: 4}), ReferenceError);
  assertEquals(4, f11({a: 4}, {b: 5}));
932 933 934
  function f12({a = eval("b")}, {b}) { return a }
  assertThrows(() => f12({}, {b: 4}), ReferenceError);
  assertEquals(4, f12({a: 4}, {b: 5}));
935 936 937 938 939 940
  (function() {
    'use strict';
    function f13({a = eval("b")}, {b}) { return a }
    assertThrows(() => f13({}, {b: 4}), ReferenceError);
    assertEquals(4, f13({a: 4}, {b: 5}));
  })();
941 942 943
  function f14({a = eval("'use strict'; b")}, {b}) { return a }
  assertThrows(() => f14({}, {b: 4}), ReferenceError);
  assertEquals(4, f14({a: 4}, {b: 5}));
944 945 946

  function f15({a = () => b}, {b}) { return a() }
  assertEquals(4, f15({a: () => 4}, {b: 5}));
947 948
  function f16({a = () => eval("b")}, {b}) { return a() }
  assertEquals(4, f16({a: () => 4}, {b: 5}));
949 950 951 952 953
  (function() {
    'use strict';
    function f17({a = () => eval("b")}, {b}) { return a() }
    assertEquals(4, f17({a: () => 4}, {b: 5}));
  })();
954 955
  function f18({a = () => eval("'use strict'; b")}, {b}) { return a() }
  assertEquals(4, f18({a: () => 4}, {b: 5}));
956 957

  // TODO(caitp): TDZ for rest parameters is not working yet.
958
  // function f30({x = a}, ...a) { return x[0] }
959
  // assertThrows(() => f30({}), ReferenceError);
960 961
  // assertEquals(4, f30({a: [4]}, 5));
  // function f31({x = eval("a")}, ...a) { return x[0] }
962
  // assertThrows(() => f31({}), ReferenceError);
963 964
  // assertEquals(4, f31({a: [4]}, 5));
  // function f32({x = eval("a")}, ...a) { 'use strict'; return x[0] }
965
  // assertThrows(() => f32({}), ReferenceError);
966 967
  // assertEquals(4, f32({a: [4]}, 5));
  // function f33({x = eval("'use strict'; a")}, ...a) { return x[0] }
968
  // assertThrows(() => f33({}), ReferenceError);
969 970
  // assertEquals(4, f33({a: [4]}, 5));

971 972 973 974
  function f34({x = function() { return a }}, ...a) { return x()[0] }
  assertEquals(4, f34({}, 4));
  function f35({x = () => a}, ...a) { return x()[0] }
  assertEquals(4, f35({}, 4));
975 976
  function f36({x = () => eval("a")}, ...a) { return x()[0] }
  assertEquals(4, f36({}, 4));
977 978 979 980 981
  (function() {
    'use strict';
    function f37({x = () => eval("a")}, ...a) { return x()[0] }
    assertEquals(4, f37({}, 4));
  })();
982 983 984 985
  function f38({x = () => { 'use strict'; return eval("a") }}, ...a) { return x()[0] }
  assertEquals(4, f38({}, 4));
  function f39({x = () => eval("'use strict'; a")}, ...a) { return x()[0] }
  assertEquals(4, f39({}, 4));
986 987 988 989 990 991 992 993 994 995 996 997 998

  // var g30 = ({x = a}, ...a) => {};
  // assertThrows(() => g30({}), ReferenceError);
  // var g31 = ({x = eval("a")}, ...a) => {};
  // assertThrows(() => g31({}), ReferenceError);
  // var g32 = ({x = eval("a")}, ...a) => { 'use strict'; };
  // assertThrows(() => g32({}), ReferenceError);
  // var g33 = ({x = eval("'use strict'; a")}, ...a) => {};
  // assertThrows(() => g33({}), ReferenceError);
  var g34 = ({x = function() { return a }}, ...a) => { return x()[0] };
  assertEquals(4, g34({}, 4));
  var g35 = ({x = () => a}, ...a) => { return x()[0] };
  assertEquals(4, g35({}, 4));
999 1000 1001
})();


1002 1003 1004 1005 1006 1007 1008 1009
(function TestDuplicatesInParameters() {
  assertThrows("'use strict';function f(x,x){}", SyntaxError);
  assertThrows("'use strict';function f({x,x}){}", SyntaxError);
  assertThrows("'use strict';function f(x, {x}){}", SyntaxError);
  assertThrows("'use strict';var f = (x,x) => {};", SyntaxError);
  assertThrows("'use strict';var f = ({x,x}) => {};", SyntaxError);
  assertThrows("'use strict';var f = (x, {x}) => {};", SyntaxError);

1010 1011 1012 1013
  function ok1(x) { var x; return x; };
  assertEquals(1, ok1(1));
  function ok2(x) { 'use strict'; { let x = 2; return x; } };
  assertEquals(2, ok2(1));
1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047
}());


(function TestShadowingOfParameters() {
  function f1({x}) { var x = 2; return x }
  assertEquals(2, f1({x: 1}));
  function f2({x}) { { var x = 2; } return x; }
  assertEquals(2, f2({x: 1}));
  function f3({x}) { var y = x; var x = 2; return y; }
  assertEquals(1, f3({x: 1}));
  function f4({x}) { { var y = x; var x = 2; } return y; }
  assertEquals(1, f4({x: 1}));
  function f5({x}, g = () => x) { var x = 2; return g(); }
  assertEquals(1, f5({x: 1}));
  function f6({x}, g = () => x) { { var x = 2; } return g(); }
  assertEquals(1, f6({x: 1}));
  function f7({x}) { var g = () => x; var x = 2; return g(); }
  assertEquals(2, f7({x: 1}));
  function f8({x}) { { var g = () => x; var x = 2; } return g(); }
  assertEquals(2, f8({x: 1}));
  function f9({x}, g = () => eval("x")) { var x = 2; return g(); }
  assertEquals(1, f9({x: 1}));

  function f10({x}, y) { var y; return y }
  assertEquals(2, f10({x: 6}, 2));
  function f11({x}, y) { var z = y; var y = 2; return z; }
  assertEquals(1, f11({x: 6}, 1));
  function f12(y, g = () => y) { var y = 2; return g(); }
  assertEquals(1, f12(1));
  function f13({x}, y, [z], v) { var x, y, z; return x*y*z*v }
  assertEquals(210, f13({x: 2}, 3, [5], 7));

  function f20({x}) { function x() { return 2 }; return x(); }
  assertEquals(2, f20({x: 1}));
1048 1049 1050
  // Annex B 3.3 function hoisting is blocked by the conflicting x declaration
  function f21({x}) { { function x() { return 2 } } return x; }
  assertEquals(1, f21({x: 1}));
1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082

  var g1 = ({x}) => { var x = 2; return x };
  assertEquals(2, g1({x: 1}));
  var g2 = ({x}) => { { var x = 2; } return x; };
  assertEquals(2, g2({x: 1}));
  var g3 = ({x}) => { var y = x; var x = 2; return y; };
  assertEquals(1, g3({x: 1}));
  var g4 = ({x}) => { { var y = x; var x = 2; } return y; };
  assertEquals(1, g4({x: 1}));
  var g5 = ({x}, g = () => x) => { var x = 2; return g(); };
  assertEquals(1, g5({x: 1}));
  var g6 = ({x}, g = () => x) => { { var x = 2; } return g(); };
  assertEquals(1, g6({x: 1}));
  var g7 = ({x}) => { var g = () => x; var x = 2; return g(); };
  assertEquals(2, g7({x: 1}));
  var g8 = ({x}) => { { var g = () => x; var x = 2; } return g(); };
  assertEquals(2, g8({x: 1}));
  var g9 = ({x}, g = () => eval("x")) => { var x = 2; return g(); };
  assertEquals(1, g9({x: 1}));

  var g10 = ({x}, y) => { var y; return y };
  assertEquals(2, g10({x: 6}, 2));
  var g11 = ({x}, y) => { var z = y; var y = 2; return z; };
  assertEquals(1, g11({x: 6}, 1));
  var g12 = (y, g = () => y) => { var y = 2; return g(); };
  assertEquals(1, g12(1));
  var g13 = ({x}, y, [z], v) => { var x, y, z; return x*y*z*v };
  assertEquals(210, g13({x: 2}, 3, [5], 7));

  var g20 = ({x}) => { function x() { return 2 }; return x(); }
  assertEquals(2, g20({x: 1}));
  var g21 = ({x}) => { { function x() { return 2 } } return x(); }
1083
  assertThrows(() => g21({x: 1}), TypeError);
1084

1085 1086 1087 1088 1089
  // These errors are not recognized in lazy parsing; see mjsunit/bugs/bug-2728.js
  assertThrows("'use strict'; (function f(x) { let x = 0; })()", SyntaxError);
  assertThrows("'use strict'; (function f({x}) { let x = 0; })()", SyntaxError);
  assertThrows("'use strict'; (function f(x) { const x = 0; })()", SyntaxError);
  assertThrows("'use strict'; (function f({x}) { const x = 0; })()", SyntaxError);
1090

1091 1092 1093 1094
  assertThrows("'use strict'; let g = (x) => { let x = 0; }", SyntaxError);
  assertThrows("'use strict'; let g = ({x}) => { let x = 0; }", SyntaxError);
  assertThrows("'use strict'; let g = (x) => { const x = 0; }", SyntaxError);
  assertThrows("'use strict'; let g = ({x}) => { const x = 0; }", SyntaxError);
1095
}());
1096 1097


1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117
(function TestArgumentsForNonSimpleParameters() {
  function f1({}, x) { arguments[1] = 0; return x }
  assertEquals(6, f1({}, 6));
  function f2({}, x) { x = 2; return arguments[1] }
  assertEquals(7, f2({}, 7));
  function f3(x, {}) { arguments[0] = 0; return x }
  assertEquals(6, f3(6, {}));
  function f4(x, {}) { x = 2; return arguments[0] }
  assertEquals(7, f4(7, {}));
  function f5(x, ...a) { arguments[0] = 0; return x }
  assertEquals(6, f5(6, {}));
  function f6(x, ...a) { x = 2; return arguments[0] }
  assertEquals(6, f6(6, {}));
  function f7({a: x}) { x = 2; return arguments[0].a }
  assertEquals(5, f7({a: 5}));
  function f8(x, ...a) { a = []; return arguments[1] }
  assertEquals(6, f8(5, 6));
}());


1118
(function TestForInOfTDZ() {
1119 1120
  assertThrows("'use strict'; let x = {}; for (let [x, y] of [x]);", ReferenceError);
  assertThrows("'use strict'; let x = {}; for (let [y, x] of [x]);", ReferenceError);
1121 1122 1123
  assertThrows("'use strict'; let x = {}; for (let [x, y] in {x});", ReferenceError);
  assertThrows("'use strict'; let x = {}; for (let [y, x] in {x});", ReferenceError);
}());
1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139


(function TestFunctionLength() {
   assertEquals(1, (function({}) {}).length);
   assertEquals(1, (function([]) {}).length);
   assertEquals(1, (function({x}) {}).length);
   assertEquals(1, (function({}, ...a) {}).length);
   assertEquals(1, (function({x}, {y} = {}) {}).length);
   assertEquals(1, (function({x}, {y} = {}, ...a) {}).length);
   assertEquals(2, (function(x, {y}, {z} = {}) {}).length);
   assertEquals(2, (function({x}, {}, {z} = {}, ...a) {}).length);
   assertEquals(1, (function(x, {y} = {}, {z}) {}).length);
   assertEquals(1, (function({x}, {y} = {}, {z}, ...a) {}).length);
   assertEquals(1, (function(x, {y} = {}, {z}, {v} = {}) {}).length);
   assertEquals(1, (function({x}, {y} = {}, {z}, {v} = {}, ...a) {}).length);
})();
1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155


(function TestDirectiveThrows() {
  "use strict";

  assertThrows(function(){ eval("function({}){'use strict';}") }, SyntaxError);
  assertThrows(function(){ eval("({}) => {'use strict';}") }, SyntaxError);
  assertThrows(
    function(){ eval("(class{foo({}) {'use strict';}});") }, SyntaxError);

  assertThrows(
    function(){ eval("function(a, {}){'use strict';}") }, SyntaxError);
  assertThrows(function(){ eval("(a, {}) => {'use strict';}") }, SyntaxError);
  assertThrows(
    function(){ eval("(class{foo(a, {}) {'use strict';}});") }, SyntaxError);
})();
1156

1157

1158 1159 1160 1161 1162
(function TestLegacyConstDestructuringInForLoop() {
  var result;
  for (const {foo} of [{foo: 1}]) { result = foo; }
  assertEquals(1, result);
})();
1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188


(function TestCatch() {
  "use strict";

  // For testing proper scoping.
  var foo = "hello", bar = "world", baz = 42;

  try {
    throw {foo: 1, bar: 2};
  } catch ({foo, bar, baz = 3}) {
    assertEquals(1, foo);
    assertEquals(2, bar);
    assertEquals(3, baz);
  }

  try {
    throw [1, 2, 3];
  } catch ([foo, ...bar]) {
    assertEquals(1, foo);
    assertEquals([2, 3], bar);
  }

  assertEquals("hello", foo);
  assertEquals("world", bar);
  assertEquals(42, baz);
1189 1190 1191

  assertEquals(undefined, eval('try {throw {foo: 1, bar: 2}} catch({foo}) {}'));
  assertEquals(undefined, eval('try {throw [1, 2, 3]} catch([x]) {}'));
1192
})();
1193

1194
// Property access as declaration target.
1195 1196 1197
assertThrows("let [o.x=1]=[]", SyntaxError);
assertThrows("let {x:o.f=1}={x:1}", SyntaxError);
assertThrows("(o.f=1)=>0", SyntaxError);
1198 1199 1200 1201 1202

// Invalidly parenthesized declaration targets.
assertThrows("for (({x}) of [{x:1}]) {}", SyntaxError);
assertThrows("for (var ({x}) of [{x:1}]) {}", SyntaxError);
assertThrows("for await (({x}) of [{x:1}]) {}", SyntaxError);