Building Enterprise JavaScript Applications

Making failure more informative

At the moment, if one of the assertions fails, we're throwing a generic Error object:

throw new Error();

When the test actually fails, the error message is not helpful because it doesn't tell us what the actual result is:

✗ Then our API should respond with a 400 HTTP status code   {}   Error       at World.<anonymous>

We can improve this by throwing an instance of AssertionError instead of just an instance of Error. AssertionError is a class provided by Node.js that allows you to specify the expected and actual outcomes.

To use it, first import it from the assert module:

import { AssertionError } from 'assert';

Then, change our step definition to the following:

Then('our API should respond with a 400 HTTP status code', ...