| // The LHS of a for-of loop is not evaluated until after the .next() method returns. | |
| var s; | |
| function f() { | |
| s += 'f'; | |
| return {}; | |
| } | |
| // Test 1: .next() throws StopIteration right away. f is never called. | |
| s = ''; | |
| for (f().x of []) | |
| s += '.'; | |
| assertEq(s, ''); | |
| // Test 2: check proper interleaving of f calls, iterator.next() calls, and the loop body. | |
| function g() { | |
| s += 'g'; | |
| yield 0; | |
| s += 'g'; | |
| yield 1; | |
| s += 'g'; | |
| } | |
| for (f().x of g()) | |
| s += '.'; | |
| assertEq(s, 'gf.gf.g'); |