Let's write unit tests for the generateValidationErrorMessage function. But first, let's convert our src/validators/errors/messages.js file into its own directory so that we can group the implementation and test code together in the same directory:
$ cd src/validators/errors$ mkdir messages$ mv messages.js messages/index.js$ touch messages/index.unit.test.js
Next, in index.unit.test.js, import the assert library and our index.js file:
import assert from 'assert';import generateValidationErrorMessage from '.';
Now, we are ready to write our tests.
