| function shouldBe(actual, expected) { |
| if (actual !== expected) |
| throw new Error('bad value: ' + actual); |
| } |
| |
| function shouldThrow(func, errorMessage) { |
| var errorThrown = false; |
| var error = null; |
| try { |
| func(); |
| } catch (e) { |
| errorThrown = true; |
| error = e; |
| } |
| if (!errorThrown) |
| throw new Error('not thrown'); |
| if (String(error) !== errorMessage) |
| throw new Error(`bad error: ${String(error)}`); |
| } |
| |
| function *gen() |
| { |
| yield new.target; |
| } |
| |
| var g = gen(); |
| shouldBe(g.next().value, undefined); |
| |
| shouldThrow(() => { |
| var g2 = new gen(); |
| }, `TypeError: function is not a constructor (evaluating 'new gen()')`); |