测试抛出错误答案

【问题标题】：Test throwing errors测试抛出错误
【发布时间】：2020-06-07 15:51:57
【问题描述】：

我正在尝试测试抛出的错误。

这是我的代码

const validatorMethod = (data) => {
  const validationResult = Object.keys(data)
    .map((key) => {
      if (!data[key] || data[key].trim() === '') {
        return key;
      }
      return true;
    });
  if (validationResult.filter((prop) => prop === true).length !== data.length) {
    return validationResult.filter((prop) => prop !== true);
  }
  return true;
};

module.exports = {
  userObjectFactory (data) {
    console.log(data);
    const invalidKeys = validatorMethod(data);
    if (invalidKeys.length === true) {
      console.log(1);
      return data;
    }
    console.log(2);
    throw new Error('One of passed properties is empty');
  },
};

这是我的测试

const userTemplate = {
  id: 1,
  email: 'a@a.a',
  password: 'zaq1@WSX',
  fullName: 'full name',
  location: 'location',
  isLookingForWork: false,
};
describe('factory should throw error on undefined, null, or ""', () => {
  it('should throw an error if some inputs are undefined', () => {
    const userWithUndefinedProperty = userTemplate;
    userWithUndefinedProperty.id = undefined;
    userWithUndefinedProperty.password = undefined;

    assert.throws(
      userObjectFactory(
        userWithUndefinedProperty, new Error('One of passed properties is empty'), // also tried "Error" and "Error('One of passed properties is empty')" without the "new"
      ),
    );
  });
});

输出

  0 passing (68ms)
  2 failing

  1) testing UserObjectFactory
       should return an object with correct data:
     Error: One of passed properties is empty
      at userObjectFactory (src\user\UserObjectFactory.js:2:1646)
      at Context.it (test\user\UserObjectFactory.test.js:33:18)

  2) testing UserObjectFactory
       factory should throw error on undefined, null, or ""
         should throw an error if some inputs are undefined:
     Error: One of passed properties is empty
      at userObjectFactory (src\user\UserObjectFactory.js:2:1646)
      at Context.it (test\user\UserObjectFactory.test.js:26:9)

【问题讨论】：

结果如何？一些事情： 1. 您通常需要将可调用传递给检查错误的方法；和 2. 您将错误作为第二个参数传递给工厂，而不是 .throws。
1.你是什么意思？ 2、你说的对，谢谢，但是改这个并没有解决问题
阅读文档：nodejs.org/api/…。您需要传递一些应该在调用时 引发错误的东西，推迟执行，否则在调用assert.throws 之前会引发错误。同样，您发布的内容的结果是什么？
@jonrsharpe 我在我的代码中发现了许多小错误，并且正在修复它们，但它仍然会抛出错误，因此它应该将其断言为 true。我正在添加输出
@jonrsharpe 如果我需要将值传递到方法中，我如何在不调用它的情况下传递它？

标签： javascript node.js unit-testing mocha.js chai

【解决方案1】：

您应该向assert.throws 传递对调用时会引发错误的函数的引用

例如

const thisIsAFunctionThatIsSupposedToThrowWhenCalled = () =>
  userObjectFactory(
    userWithUndefinedProperty,
    new Error("One of passed properties is empty") // also tried "Error" and "Error('One of passed properties is empty')" without the "new"
  );

assert.throws(thisIsAFunctionThatIsSupposedToThrowWhenCalled);

或

assert.throws(
  () => userObjectFactory(
    userWithUndefinedProperty, new Error('One of passed properties is empty'), // also tried "Error" and "Error('One of passed properties is empty')" without the "new"
  )
)

【讨论】：