CODEWITHSUNDEEP
javascriptnode.jsunit-testingmocha.jschai
Alex Ironside
Alex Ironside

Reputation: 5039

Test throwing errors

I'm trying to test errors throwing.

Here's my code

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');
  },
};

Here is my test

const userTemplate = {
  id: 1,
  email: '[email protected]',
  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"
      ),
    );
  });
});

the output

  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)

Upvotes: 0

Views: 156

Answers (1)

Teneff
Teneff

Reputation: 32158

You should pass to assert.throws a reference to a function that when called throws an error

e.g.

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);

or

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"
  )
)

Upvotes: 1

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