In this short but important chapter, we learned about software testing.
We took the opportunity to remind you of the importance of software/code quality in general and of testing in particular. We briefly covered what testing is, as well as different types of tests that can be created to increase the confidence in what we build, mocks and stubs, and many other elements.
We also reviewed some testing approaches, such as TDD and BDD, as well as concepts such as the test pyramid, test automation, and many others.
While covering this subject, we also introduced different testing tools and libraries that are currently heavily used in the JavaScript/TypeScript ecosystem. We then presented the Jest testing library (https://jestjs.io).
After adding and configuring Jest, we wrote a few unit tests together and used jest-fetch-mock (https://github.com/jefflau/jest-fetch-mock),...