1 files changed, 1382 insertions, 0 deletions
diff --git a/deps/v8/test/mjsunit/es6/iterator-close.js b/deps/v8/test/mjsunit/es6/iterator-close.js
new file mode 100644
index 0000000000..fd8f361e5e
--- /dev/null
+++ b/deps/v8/test/mjsunit/es6/iterator-close.js
@@ -0,0 +1,1382 @@
+// Copyright 2016 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* g() { yield 42; return 88 };
+
+
+// Return method is "undefined".
+{
+  g.prototype.return = null;
+
+
+  assertEquals(undefined, (() => {
+    for (var x of g()) { break; }
+  })());
+
+  assertEquals(undefined, (() => {
+    for (let x of g()) { break; }
+  })());
+
+  assertEquals(undefined, (() => {
+    for (const x of g()) { break; }
+  })());
+
+  assertEquals(undefined, (() => {
+    for (x of g()) { break; }
+  })());
+
+
+  assertThrowsEquals(() => {
+    for (var x of g()) { throw 42; }
+  }, 42);
+
+  assertThrowsEquals(() => {
+    for (let x of g()) { throw 42; }
+  }, 42);
+
+  assertThrowsEquals(() => {
+    for (const x of g()) { throw 42; }
+  }, 42);
+
+  assertThrowsEquals(() => {
+    for (x of g()) { throw 42; }
+  }, 42);
+
+
+  assertEquals(42, (() => {
+    for (var x of g()) { return 42; }
+  })());
+
+  assertEquals(42, (() => {
+    for (let x of g()) { return 42; }
+  })());
+
+  assertEquals(42, (() => {
+    for (const x of g()) { return 42; }
+  })());
+
+  assertEquals(42, (() => {
+    for (x of g()) { return 42; }
+  })());
+
+
+  assertEquals(42, eval('for (var x of g()) { x; }'));
+
+  assertEquals(42, eval('for (let x of g()) { x; }'));
+
+  assertEquals(42, eval('for (const x of g()) { x; }'));
+
+  assertEquals(42, eval('for (x of g()) { x; }'));
+
+
+  assertEquals(42, (() => {
+    var [x] = g(); return x;
+  })());
+
+  assertEquals(42, (() => {
+    let [x] = g(); return x;
+  })());
+
+  assertEquals(42, (() => {
+    const [x] = g(); return x;
+  })());
+
+  assertEquals(42, (() => {
+    [x] = g(); return x;
+  })());
+
+  assertEquals(42,
+    (([x]) => x)(g())
+  );
+}
+
+
+// Return method is not callable.
+{
+  g.prototype.return = 666;
+
+
+  assertThrows(() => {
+    for (var x of g()) { break; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (let x of g()) { break; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (const x of g()) { break; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (x of g()) { break; }
+  }, TypeError);
+
+
+  assertThrows(() => {
+    for (var x of g()) { throw 666; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (let x of g()) { throw 666; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (const x of g()) { throw 666; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (x of g()) { throw 666; }
+  }, TypeError);
+
+
+  assertThrows(() => {
+    for (var x of g()) { return 666; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (let x of g()) { return 666; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (const x of g()) { return 666; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (x of g()) { return 666; }
+  }, TypeError);
+
+
+  assertEquals(42, eval('for (var x of g()) { x; }'));
+
+  assertEquals(42, eval('for (let x of g()) { x; }'));
+
+  assertEquals(42, eval('for (const x of g()) { x; }'));
+
+  assertEquals(42, eval('for (x of g()) { x; }'));
+
+
+  assertThrows(() => {
+    var [x] = g(); return x;
+  }, TypeError);
+
+  assertThrows(() => {
+    let [x] = g(); return x;
+  }, TypeError);
+
+  assertThrows(() => {
+    const [x] = g(); return x;
+  }, TypeError);
+
+  assertThrows(() => {
+    [x] = g(); return x;
+  }, TypeError);
+
+  assertThrows(() => {
+    (([x]) => x)(g());
+  }, TypeError);
+}
+
+
+// Return method does not return an object.
+{
+  g.prototype.return = () => 666;
+
+
+  assertThrows(() => {
+    for (var x of g()) { break; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (let x of g()) { break; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (const x of g()) { break; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (x of g()) { break; }
+  }, TypeError);
+
+
+  // Throw from the body of a for loop 'wins' vs throw
+  // originating from a bad 'return' value.
+
+  assertThrowsEquals(() => {
+    for (var x of g()) { throw 666; }
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (let x of g()) { throw 666; }
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (const x of g()) { throw 666; }
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (x of g()) { throw 666; }
+  }, 666);
+
+
+  assertThrows(() => {
+    for (var x of g()) { return 666; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (let x of g()) { return 666; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (const x of g()) { return 666; }
+  }, TypeError);
+
+  assertThrows(() => {
+    for (x of g()) { return 666; }
+  }, TypeError);
+
+
+  assertEquals(42, eval('for (var x of g()) { x; }'));
+
+  assertEquals(42, eval('for (let x of g()) { x; }'));
+
+  assertEquals(42, eval('for (const x of g()) { x; }'));
+
+  assertEquals(42, eval('for (x of g()) { x; }'));
+
+
+  assertThrows(() => {
+    var [x] = g(); return x;
+  }, TypeError);
+
+  assertThrows(() => {
+    let [x] = g(); return x;
+  }, TypeError);
+
+  assertThrows(() => {
+    const [x] = g(); return x;
+  }, TypeError);
+
+  assertThrows(() => {
+    [x] = g(); return x;
+  }, TypeError);
+
+  assertThrows(() => {
+    (([x]) => x)(g());
+  }, TypeError);
+}
+
+
+// Return method returns an object.
+{
+  let log = [];
+  g.prototype.return = (...args) => { log.push(args); return {} };
+
+
+  log = [];
+  for (var x of g()) { break; }
+  assertEquals([[]], log);
+
+  log = [];
+  for (let x of g()) { break; }
+  assertEquals([[]], log);
+
+  log = [];
+  for (const x of g()) { break; }
+  assertEquals([[]], log);
+
+  log = [];
+  for (x of g()) { break; }
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (var x of g()) { throw 42; }
+  }, 42);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g()) { throw 42; }
+  }, 42);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (const x of g()) { throw 42; }
+  }, 42);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (x of g()) { throw 42; }
+  }, 42);
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertEquals(42, (() => {
+    for (var x of g()) { return 42; }
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    for (let x of g()) { return 42; }
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    for (const x of g()) { return 42; }
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    for (x of g()) { return 42; }
+  })());
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertEquals(42, eval('for (var x of g()) { x; }'));
+  assertEquals([], log);
+
+  log = [];
+  assertEquals(42, eval('for (let x of g()) { x; }'));
+  assertEquals([], log);
+
+  log = [];
+  assertEquals(42, eval('for (const x of g()) { x; }'));
+  assertEquals([], log);
+
+  log = [];
+  assertEquals(42, eval('for (x of g()) { x; }'));
+  assertEquals([], log);
+
+
+  // Even if doing the assignment throws, still call return
+  log = [];
+  x = { set attr(_) { throw 1234; } };
+  assertThrowsEquals(() => {
+    for (x.attr of g()) { throw 456; }
+  }, 1234);
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertEquals(42, (() => {
+    var [x] = g(); return x;
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    let [x] = g(); return x;
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    const [x] = g(); return x;
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    [x] = g(); return x;
+  })());
+  assertEquals([[]], log);
+
+  log = []
+  assertEquals(42,
+    (([x]) => x)(g())
+  );
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertEquals(42, (() => {
+    var [x,] = g(); return x;
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    let [x,] = g(); return x;
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    const [x,] = g(); return x;
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    [x,] = g(); return x;
+  })());
+  assertEquals([[]], log);
+
+  log = []
+  assertEquals(42,
+    (([x,]) => x)(g())
+  );
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertEquals(42, (() => {
+    var [x,,] = g(); return x;
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    let [x,,] = g(); return x;
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    const [x,,] = g(); return x;
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals(42, (() => {
+    [x,,] = g(); return x;
+  })());
+  assertEquals([], log);
+
+  log = []
+  assertEquals(42,
+    (([x,,]) => x)(g())
+  );
+  assertEquals([], log);
+
+
+  log = [];
+  assertEquals([42, undefined], (() => {
+    var [x, y] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42, undefined], (() => {
+    let [x, y] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42, undefined], (() => {
+    const [x, y] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42, undefined], (() => {
+    [x, y] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = []
+  assertEquals([42, undefined],
+    (([x, y]) => [x, y])(g())
+  );
+  assertEquals([], log);
+
+
+  log = [];
+  assertEquals([42], (() => {
+    var [...x] = g(); return x;
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42], (() => {
+    let [...x] = g(); return x;
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42], (() => {
+    const [...x] = g(); return x;
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42], (() => {
+    [...x] = g(); return x;
+  })());
+  assertEquals([], log);
+
+  log = []
+  assertEquals([42],
+    (([...x]) => x)(g())
+  );
+  assertEquals([], log);
+
+
+  log = [];
+  assertEquals([42, []], (() => {
+    var [x, ...y] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42, []], (() => {
+    let [x, ...y] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42, []], (() => {
+    const [x, ...y] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42, []], (() => {
+    [x, ...y] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = []
+  assertEquals([42, []],
+    (([x, ...y]) => [x, y])(g())
+  );
+  assertEquals([], log);
+
+
+  log = [];
+  assertEquals([], (() => {
+    var [] = g(); return [];
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals([], (() => {
+    let [] = g(); return [];
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals([], (() => {
+    const [] = g(); return [];
+  })());
+  assertEquals([[]], log);
+
+  log = [];
+  assertEquals([], (() => {
+    [] = g(); return [];
+  })());
+  assertEquals([[]], log);
+
+  log = []
+  assertEquals([],
+    (([]) => [])(g())
+  );
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertEquals([], (() => {
+    var [...[]] = g(); return [];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([], (() => {
+    let [...[]] = g(); return [];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([], (() => {
+    const [...[]] = g(); return [];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([], (() => {
+    [...[]] = g(); return [];
+  })());
+  assertEquals([], log);
+
+  log = []
+  assertEquals([],
+    (([...[]]) => [])(g())
+  );
+  assertEquals([], log);
+
+
+  log = [];
+  assertEquals([42], (() => {
+    var [...[x]] = g(); return [x];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42], (() => {
+    let [...[x]] = g(); return [x];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42], (() => {
+    const [...[x]] = g(); return [x];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42], (() => {
+    [...[x]] = g(); return [x];
+  })());
+  assertEquals([], log);
+
+  log = []
+  assertEquals([42],
+    (([...[x]]) => [x])(g())
+  );
+  assertEquals([], log);
+
+
+  log = [];
+  assertEquals([42, undefined], (() => {
+    var [...[x, y]] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42, undefined], (() => {
+    let [...[x, y]] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42, undefined], (() => {
+    const [...[x, y]] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = [];
+  assertEquals([42, undefined], (() => {
+    [...[x, y]] = g(); return [x, y];
+  })());
+  assertEquals([], log);
+
+  log = []
+  assertEquals([42, undefined],
+    (([...[x, y]]) => [x, y])(g())
+  );
+  assertEquals([], log);
+
+
+  log = []
+  assertThrowsEquals(() => {
+    let x = { set foo(_) { throw 666; } };
+    [x.foo] = g();
+  }, 666);
+  assertEquals([[]], log);
+
+
+  log = []
+  assertThrows(() => {
+    var [[]] = g();
+  }, TypeError);
+  assertEquals([[]], log);
+
+  log = []
+  assertThrows(() => {
+    let [[]] = g();
+  }, TypeError);
+  assertEquals([[]], log);
+
+  log = []
+  assertThrows(() => {
+    const [[]] = g();
+  }, TypeError);
+  assertEquals([[]], log);
+
+  log = []
+  assertThrows(() => {
+    [[]] = g();
+  }, TypeError);
+  assertEquals([[]], log);
+
+  log = []
+  assertThrows(() => {
+    (([[]]) => 0)(g());
+  }, TypeError);
+  assertEquals([[]], log);
+
+
+  log = []
+  assertThrows(() => {
+    var [...[[]]] = g();
+  }, TypeError);
+  assertEquals([], log);
+
+  log = []
+  assertThrows(() => {
+    let [...[[]]] = g();
+  }, TypeError);
+  assertEquals([], log);
+
+  log = []
+  assertThrows(() => {
+    const [...[[]]] = g();
+  }, TypeError);
+  assertEquals([], log);
+
+  log = []
+  assertThrows(() => {
+    [...[[]]] = g();
+  }, TypeError);
+  assertEquals([], log);
+
+  log = []
+  assertThrows(() => {
+    (([...[[]]]) => 0)(g());
+  }, TypeError);
+  assertEquals([], log);
+
+
+  {
+    let backup = Array.prototype[Symbol.iterator];
+    Array.prototype[Symbol.iterator] = () => g();
+
+
+    log = [];
+    assertDoesNotThrow(() => {
+      var [x, ...[y]] = [1, 2, 3]
+    });
+    assertEquals(log, [[]]);
+
+    log = [];
+    assertDoesNotThrow(() => {
+      let [x, ...[y]] = [1, 2, 3];
+    });
+    assertEquals(log, [[]]);
+
+    log = [];
+    assertDoesNotThrow(() => {
+      const [x, ...[y]] = [1, 2, 3];
+    });
+    assertEquals(log, [[]]);
+
+    log = [];
+    assertDoesNotThrow(() => {
+      (([x, ...[y]]) => {})([1, 2, 3]);
+    });
+    assertEquals(log, [[]]);
+
+
+    log = [];
+    assertThrows(() => {
+      var [x, ...[[]]] = [1, 2, 3];
+    }, TypeError);
+    assertEquals(log, [[]]);
+
+    log = [];
+    assertThrows(() => {
+      let [x, ...[[]]] = [1, 2, 3];
+    }, TypeError);
+    assertEquals(log, [[]]);
+
+    log = [];
+    assertThrows(() => {
+      const [x, ...[[]]] = [1, 2, 3];
+    }, TypeError);
+    assertEquals(log, [[]]);
+
+    log = [];
+    assertThrows(() => {
+      (([x, ...[[]]]) => {})([1, 2, 3]);
+    }, TypeError);
+    assertEquals(log, [[]]);
+
+
+    log = [];
+    assertDoesNotThrow(() => {
+      var [x, ...[...y]] = [1, 2, 3];
+    });
+    assertEquals(log, []);
+
+    log = [];
+    assertDoesNotThrow(() => {
+      let [x, ...[...y]] = [1, 2, 3];
+    });
+    assertEquals(log, []);
+
+    log = [];
+    assertDoesNotThrow(() => {
+      const [x, ...[...y]] = [1, 2, 3];
+    });
+    assertEquals(log, []);
+
+    log = [];
+    assertDoesNotThrow(() => {
+      (([x, ...[...y]]) => {})([1, 2, 3]);
+    });
+    assertEquals(log, []);
+
+
+    Array.prototype[Symbol.iterator] = backup;
+  }
+}
+
+
+// Return method throws.
+{
+  let log = [];
+  g.prototype.return = (...args) => { log.push(args); throw 23 };
+
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (var x of g()) { break; }
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g()) { break; }
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (const x of g()) { break; }
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (x of g()) { break; }
+  }, 23);
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (var x of g()) { throw 42; }
+  }, 42);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g()) { throw 42; }
+  }, 42);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (const x of g()) { throw 42; }
+  }, 42);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (x of g()) { throw 42; }
+  }, 42);
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (var x of g()) { return 42; }
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g()) { return 42; }
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (const x of g()) { return 42; }
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (x of g()) { return 42; }
+  }, 23);
+  assertEquals([[]], log);
+
+
+  log = [];
+  assertEquals(42, eval('for (var x of g()) { x; }'));
+  assertEquals([], log);
+
+  log = [];
+  assertEquals(42, eval('for (let x of g()) { x; }'));
+  assertEquals([], log);
+
+  log = [];
+  assertEquals(42, eval('for (const x of g()) { x; }'));
+  assertEquals([], log);
+
+  log = [];
+  assertEquals(42, eval('for (x of g()) { x; }'));
+  assertEquals([], log);
+
+
+  log = [];
+  assertThrowsEquals(() => {
+    var [x] = g(); return x;
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    let [x] = g(); return x;
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    const [x] = g(); return x;
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    [x] = g(); return x;
+  }, 23);
+  assertEquals([[]], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    (([x]) => x)(g())
+  }, 23);
+  assertEquals([[]], log);
+}
+
+
+// Next method throws.
+{
+  let closed = false;
+  g.prototype.next = () => { throw 666; };
+  g.prototype.return = () => { closed = true; };
+
+
+  assertThrowsEquals(() => {
+    for (var x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (let x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (const x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    var [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    let [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    const [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    (([x]) => x)(g());
+  }, 666);
+
+  assertThrowsEquals(() => {
+    var [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    let [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    const [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    (([...x]) => x)(g());
+  }, 666);
+
+
+  assertFalse(closed);
+}
+
+
+// Value throws.
+{
+  let closed = false;
+  g.prototype.next = () => ({get value() {throw 666}});
+  g.prototype.return = () => { closed = true; };
+
+
+  assertThrowsEquals(() => {
+    for (var x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (let x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (const x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    var [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    let [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    const [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    (([x]) => x)(g());
+  }, 666);
+
+  assertThrowsEquals(() => {
+    var [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    let [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    const [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    (([...x]) => x)(g());
+  }, 666);
+
+
+  assertFalse(closed);
+}
+
+
+// Done throws.
+{
+  let closed = false;
+  g.prototype.next = () => ({get done() {throw 666}});
+  g.prototype.return = () => { closed = true; };
+
+
+  assertThrowsEquals(() => {
+    for (var x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (let x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (const x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    for (x of g()) {}
+  }, 666);
+
+  assertThrowsEquals(() => {
+    var [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    let [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    const [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    [x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    (([x]) => x)(g());
+  }, 666);
+
+  assertThrowsEquals(() => {
+    var [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    let [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    const [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    [...x] = g();
+  }, 666);
+
+  assertThrowsEquals(() => {
+    (([...x]) => x)(g());
+  }, 666);
+
+
+  assertFalse(closed);
+}
+
+
+// Nested loops.
+{
+  function* g1() { yield 1; yield 2; throw 3; }
+  function* g2() { yield -1; yield -2; throw -3; }
+
+  assertDoesNotThrow(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+        if (y == -2) break;
+      }
+      if (x == 2) break;
+    }
+  }, -3);
+
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+      }
+    }
+  }, -3);
+
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+        if (y == -2) break;
+      }
+    }
+  }, 3);
+
+  assertDoesNotThrow(() => {
+    l: for (let x of g1()) {
+      for (let y of g2()) {
+        if (y == -2) break l;
+      }
+    }
+  });
+
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+        throw 4;
+      }
+    }
+  }, 4);
+
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+        if (y == -2) throw 4;
+      }
+    }
+  }, 4);
+
+  let log = [];
+  g1.prototype.return = () => { log.push(1); throw 5 };
+  g2.prototype.return = () => { log.push(2); throw -5 };
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+        if (y == -2) break;
+      }
+      if (x == 2) break;
+    }
+  }, -5);
+  assertEquals([2, 1], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+      }
+    }
+  }, -3);
+  assertEquals([1], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+        if (y == -2) break;
+      }
+    }
+  }, -5);
+  assertEquals([2, 1], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    l: for (let x of g1()) {
+      for (let y of g2()) {
+        if (y == -2) break l;
+      }
+    }
+  }, -5);
+  assertEquals([2, 1], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+        throw 4;
+      }
+    }
+  }, 4);
+  assertEquals([2, 1], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      for (let y of g2()) {
+        if (y == -2) throw 4;
+      }
+    }
+  }, 4);
+  assertEquals([2, 1], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      try {
+        for (let y of g2()) {
+        }
+      } catch (_) {}
+    }
+  }, 3);
+  assertEquals([], log);
+
+  log = [];
+  assertThrowsEquals(() => {
+    for (let x of g1()) {
+      try {
+        for (let y of g2()) {
+        }
+      } catch (_) {}
+      if (x == 2) break;
+    }
+  }, 5);
+  assertEquals([1], log);
+}
+
+
+// yield*, argument's return method is "undefined".
+function TestYieldStarWithoutReturn(get_iterable) {
+  assertTrue(get_iterable().return == undefined);
+
+  function* g() { yield* get_iterable() }
+
+  {
+    let gen = g();
+    assertEquals({value: 1, done: false}, gen.next());
+    assertEquals({value: undefined, done: true}, gen.return());
+  }
+
+  assertEquals(42, (() => {
+    for (let x of g()) break;
+    return 42;
+  })());
+
+  assertEquals(42, (() => {
+    for (let x of g()) return 42;
+  })());
+
+  assertThrowsEquals(() => {
+    for (let x of g()) throw 42;
+  }, 42);
+}
+{
+  let get_iterable1 = () => [1, 2];
+  let get_iterable2 = function*() { yield 1; yield 2 };
+  get_iterable2.prototype.return = null;
+  TestYieldStarWithoutReturn(get_iterable1);
+  TestYieldStarWithoutReturn(get_iterable2);
+}
+
+
+// yield*, argument's return method is defined.
+{
+  let get_iterable = function*() { yield 1; yield 2 };
+  const obj = {};
+  get_iterable.prototype.return = (...args) => obj;
+
+  function* g() { yield* get_iterable() }
+
+  {
+    let gen = g();
+    assertEquals({value: 1, done: false}, gen.next());
+    assertSame(obj, gen.return());
+    assertSame(obj, gen.return());
+    assertSame(obj, gen.return());
+    assertEquals({value: 2, done: false}, gen.next());
+    assertSame(obj, gen.return());
+    assertSame(obj, gen.return());
+    assertSame(obj, gen.return());
+    assertEquals({value: undefined, done: true}, gen.next());
+    assertEquals({value: undefined, done: true}, gen.return());
+    assertEquals({value: undefined, done: true}, gen.return());
+  }
+
+  assertEquals(42, (() => {
+    for (let x of g()) break;
+    return 42;
+  })());
+
+  assertEquals(42, (() => {
+    for (let x of g()) return 42;
+  })());
+
+  assertThrowsEquals(() => {
+    for (let x of g()) throw 42;
+  }, 42);
+}