javascript - 预期调用一个断言但收到零个断言调用

Question

我正在尝试使用 Jest 测试一个方法...该方法应该返回 Promise.reject() 。

这是我写的代码:

test('testing Invalid Response Type', () => {       
        const client = new DataClient();

        client.getSomeData().then(response => {
            console.log("We got data: "+ response);
        }).catch(e => {
            console.log("in catch");
            expect(e).toBeInstanceOf(IncorrectResponseTypeError);

        });
        expect.assertions(1);

  });

当我运行测试时，它打印“in catch”但失败并出现以下异常: 预期调用一个断言但收到零个断言调用。

console.log src/data/dataclient.test.js:25
      in catch

  ● testing Invalid Response Type

    expect.assertions(1)

    Expected one assertion to be called but received zero assertion calls.

      at extractExpectedAssertionsErrors (node_modules/expect/build/extract_expected_assertions_errors.js:37:19)
          at <anonymous>
      at process._tickCallback (internal/process/next_tick.js:188:7)

Answer 1

我通过在代码块前添加 return 语句解决了这个问题。使用 return 语句，函数将等待 catch block 完成.. 因此将执行 expect..

test('testing Invalid Response Type', () => {       
    const client = new DataClient();
    return client.getSomeData().then(response => {
            console.log("We got data: "+ response);
        }).catch(e => {
            console.log("in catch");
            expect(e).toBeInstanceOf(IncorrectResponseTypeError);

        });
        expect.assertions(1);
   });