Tests in React and React Native: Demystifying E2E, Unit, and Functional Tests

Ah, tests! A word every developer has heard, but whose true value is often underestimated. In the bustling world of React and React Native development, tests play a vital role. But why exactly are they so important? And how to navigate the maze of E2E, unit, and functional tests? Let's explore this together.

A. Quality and Reliability How can you ensure your dish is well-seasoned without tasting it? Having tests is having a safeguard, your security that allows you to be serene during your production deployment. They ensure that your code works as expected, offering a reliable user experience. B. Time and Money Savings A bug detected early is less costly to correct than if discovered after deployment. Tests help identify issues before they become critical, avoiding hours of debugging and financial losses. The essential sticking point on this part is that doing tests is often considered more of a "brake" than anything else. It takes more time to deliver, installing testing libraries is sometimes long and complicated (Detox, for example), and conducting tests takes time. Therefore, we spend more time on each new feature to create, but it's a real investment that allows us to avoid a bug that would pass in production, for example, and that would take a good week to debug. Not to mention the stress and the bad repercussions that this could have on the figures or the reputation of the company. C. Ease of Integration and Collaboration In a world where teamwork is the norm, tests ensure that new features integrate seamlessly with the old ones, thus avoiding regressions.

A. Unit Tests Unit tests are like checking the ingredients of a recipe one by one. You test each function or component in isolation to ensure its proper functioning.