// Options: --block-binding function* gen() { yield new String('abc'); yield new String('def'); } var expectedHeads = ['a', 'd']; var expectedTails = [['b', 'c'], ['e','f']]; var i = 0; for (var [head, ...tail] of gen()) { assert.equal(expectedHeads[i], head); assertArrayEquals(expectedTails[i], tail); i++; } assert.equal(2, i); { let x = 42; for (let {length: x} of gen()) { assert.equal(3, x); } assert.equal(42, x); } var k; for ({length: k} of [new String('abc')]) // No block assert.equal(3, k);