v8/test/mjsunit/harmony/generators-iteration.js

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// Flags: --harmony-generators --expose-gc

// Test generator iteration.

var GeneratorFunction = (function*(){yield 1;}).__proto__.constructor;

function TestGenerator(g, expected_values_for_next,
                       send_val, expected_values_for_send) {
  function testNext(thunk) {
    var iter = thunk();
    for (var i = 0; i < expected_values_for_next.length; i++) {
      assertEquals(expected_values_for_next[i], iter.next());
    }
    assertThrows(function() { iter.next(); }, Error);
  }
  function testSend(thunk) {
    var iter = thunk();
    for (var i = 0; i < expected_values_for_send.length; i++) {
      assertEquals(expected_values_for_send[i], iter.send(send_val));
    }
    assertThrows(function() { iter.send(send_val); }, Error);
  }
  function testThrow(thunk) {
    for (var i = 0; i < expected_values_for_next.length; i++) {
      var iter = thunk();
      for (var j = 0; j < i; j++) {
        assertEquals(expected_values_for_next[j], iter.next());
      }
      function Sentinel() {}
      assertThrows(function () { iter.throw(new Sentinel); }, Sentinel);
      assertThrows(function () { iter.next(); }, Error);
    }
  }

  testNext(g);
  testSend(g);
  testThrow(g);

  if (g instanceof GeneratorFunction) {
    testNext(function() { return new g(); });
    testSend(function() { return new g(); });
    testThrow(function() { return new g(); });
  }
}

TestGenerator(function* g1() { },
              [undefined],
              "foo",
              [undefined]);

TestGenerator(function* g2() { yield 1; },
              [1, undefined],
              "foo",
              [1, undefined]);

TestGenerator(function* g3() { yield 1; yield 2; },
              [1, 2, undefined],
              "foo",
              [1, 2, undefined]);

TestGenerator(function* g4() { yield 1; yield 2; return 3; },
              [1, 2, 3],
              "foo",
              [1, 2, 3]);

TestGenerator(function* g5() { return 1; },
              [1],
             "foo",
              [1]);

TestGenerator(function* g6() { var x = yield 1; return x; },
              [1, undefined],
              "foo",
              [1, "foo"]);

TestGenerator(function* g7() { var x = yield 1; yield 2; return x; },
              [1, 2, undefined],
              "foo",
              [1, 2, "foo"]);

TestGenerator(function* g8() { for (var x = 0; x < 4; x++) { yield x; } },
              [0, 1, 2, 3, undefined],
              "foo",
              [0, 1, 2, 3, undefined]);

// Generator with arguments.
TestGenerator(
    function g9() {
      return (function*(a, b, c, d) {
        yield a; yield b; yield c; yield d;
      })("fee", "fi", "fo", "fum");
    },
    ["fee", "fi", "fo", "fum", undefined],
    "foo",
    ["fee", "fi", "fo", "fum", undefined]);

// Too few arguments.
TestGenerator(
    function g10() {
      return (function*(a, b, c, d) {
        yield a; yield b; yield c; yield d;
      })("fee", "fi");
    },
    ["fee", "fi", undefined, undefined, undefined],
    "foo",
    ["fee", "fi", undefined, undefined, undefined]);

// Too many arguments.
TestGenerator(
    function g11() {
      return (function*(a, b, c, d) {
        yield a; yield b; yield c; yield d;
      })("fee", "fi", "fo", "fum", "I smell the blood of an Englishman");
    },
    ["fee", "fi", "fo", "fum", undefined],
    "foo",
    ["fee", "fi", "fo", "fum", undefined]);

// The arguments object.
TestGenerator(
    function g12() {
      return (function*(a, b, c, d) {
        for (var i = 0; i < arguments.length; i++) {
          yield arguments[i];
        }
      })("fee", "fi", "fo", "fum", "I smell the blood of an Englishman");
    },
    ["fee", "fi", "fo", "fum", "I smell the blood of an Englishman",
     undefined],
    "foo",
    ["fee", "fi", "fo", "fum", "I smell the blood of an Englishman",
     undefined]);

// Access to captured free variables.
TestGenerator(
    function g13() {
      return (function(a, b, c, d) {
        return (function*() {
          yield a; yield b; yield c; yield d;
        })();
      })("fee", "fi", "fo", "fum");
    },
    ["fee", "fi", "fo", "fum", undefined],
    "foo",
    ["fee", "fi", "fo", "fum", undefined]);

// Abusing the arguments object.
TestGenerator(
    function g14() {
      return (function*(a, b, c, d) {
        arguments[0] = "Be he live";
        arguments[1] = "or be he dead";
        arguments[2] = "I'll grind his bones";
        arguments[3] = "to make my bread";
        yield a; yield b; yield c; yield d;
      })("fee", "fi", "fo", "fum");
    },
    ["Be he live", "or be he dead", "I'll grind his bones", "to make my bread",
     undefined],
    "foo",
    ["Be he live", "or be he dead", "I'll grind his bones", "to make my bread",
     undefined]);

// Abusing the arguments object: strict mode.
TestGenerator(
    function g15() {
      return (function*(a, b, c, d) {
        "use strict";
        arguments[0] = "Be he live";
        arguments[1] = "or be he dead";
        arguments[2] = "I'll grind his bones";
        arguments[3] = "to make my bread";
        yield a; yield b; yield c; yield d;
      })("fee", "fi", "fo", "fum");
    },
    ["fee", "fi", "fo", "fum", undefined],
    "foo",
    ["fee", "fi", "fo", "fum", undefined]);

// GC.
TestGenerator(function* g16() { yield "baz"; gc(); yield "qux"; },
              ["baz", "qux", undefined],
              "foo",
              ["baz", "qux", undefined]);

// Receivers.
TestGenerator(
    function g17() {
      function* g() { yield this.x; yield this.y; }
      var o = { start: g, x: 1, y: 2 };
      return o.start();
    },
    [1, 2, undefined],
    "foo",
    [1, 2, undefined]);

TestGenerator(
    function g18() {
      function* g() { yield this.x; yield this.y; }
      var iter = new g;
      iter.x = 1;
      iter.y = 2;
      return iter;
    },
    [1, 2, undefined],
    "foo",
    [1, 2, undefined]);

TestGenerator(
    function* g() {
      var x = 1;
      yield x;
      with({x:2}) { yield x; }
      yield x;
    },
    [1, 2, 1, undefined],
    "foo",
    [1, 2, 1, undefined]);

function TestRecursion() {
  function TestNextRecursion() {
    function* g() { yield iter.next(); }
    var iter = g();
    return iter.next();
  }
  function TestSendRecursion() {
    function* g() { yield iter.send(42); }
    var iter = g();
    return iter.next();
  }
  function TestThrowRecursion() {
    function* g() { yield iter.throw(1); }
    var iter = g();
    return iter.next();
  }
  assertThrows(TestNextRecursion, Error);
  assertThrows(TestSendRecursion, Error);
  assertThrows(TestThrowRecursion, Error);
}
TestRecursion();