Jest - 当测试失败时，将参数记录到测试内部调用的函数中

Question

我有一个 Jest 测试，描述为：

it('Full name must be >= 3 letters', () => {
    ['', 'a', 'ab', 'a ', 'a    ', '     a'].forEach((fullName) => {
      expect(() => userBuilder.build({ fullName })).toThrowError();
    });
  });

当任何迭代失败时，测试失败并指向expect 行：

user › Full name must be >= 3 letters

    expect(received).toThrowError()

    Received function did not throw

      15 |     ['', 'a', 'ab', 'a ', 'a    ', '     a', 'asdf'].forEach((fullName) => {
      16 |       console.debug('testing', fullName);
    > 17 |       expect(() => userBuilder.build({ fullName })).toThrowError();
         |                                                     ^
      18 |     });
      19 |   });
      20 |

      at src/api/user/user.test.ts:17:53
          at Array.forEach (<anonymous>)
      at Object.<anonymous> (src/api/user/user.test.ts:15:54)

这不是很有帮助，因为它处于循环中。当expect 失败时，我需要知道在迭代中作为fullName 传递了哪些参数。

来自this SO question，我知道我可以使用类似
test.each([...])('Full name must be >= 3 letters, testing: %s'){...
但是这里每次迭代都被认为是一个单独的测试，我在数十个不同的测试中有数百个这样的迭代（全名必须 Full name must be >= 3 letters, testing: 文本。

我知道我可以 console.debug('testing', fullName) 进行每次迭代，但它会记录每次迭代的输出，并在每个输出周围添加一些详细信息，并且它不会打印出失败的消息，因此通过多次测试，很难找出哪个迭代在哪个测试中失败。我不知道如何仅在期望失败时记录输出。

对于测试运行者来说，这似乎是一件很简单的事情，我敢肯定我一定在这里遗漏了一些东西。

不确定它是否重要，但我正在将 ts-jest 用于打字稿。

Answer 1

使用describe 对验证规则进行分组，然后使用test.each 或forEach 进行测试。

describe('Full name must be >= 3 letters', () => {
  ['', 'a', 'ab', 'a ', 'a    ', '     a'].forEach((fullName) => {
    it(`should throw error when full name is "${fullName}"`, () => {
      expect(() => userBuilder.build({ fullName })).toThrowError();
    });
  });
});

然后，失败消息将如下所示：

  Full name must be >= 3 letters
    ✓ should throw error when full name is "" (9 ms)
    ✓ should throw error when full name is "a" (1 ms)
    ✕ should throw error when full name is "ab" (1 ms)
    ✓ should throw error when full name is "a " (1 ms)
    ✓ should throw error when full name is "a    "
    ✓ should throw error when full name is "     a"

  ● Full name must be >= 3 letters › should throw error when full name is "ab"

    expect(received).toThrowError()

    Received function did not throw

      10 |   ['', 'a', 'ab', 'a ', 'a    ', '     a'].forEach((fullName) => {
      11 |     it(`should throw error when full name is "${fullName}"`, () => {
    > 12 |       expect(() => userBuilder.build({ fullName })).toThrowError();
         |                                                     ^
      13 |     });
      14 |   });
      15 | });