Internationalization
react-intl is the standard i18n library for React applications built on the FormatJS ecosystem. Testing it well means more than verifying that text appears—it means asserting that the correct translation appears, that pluralization rules are respected, and that date and number formatting matches locale expectations. This guide covers the
Testing
Jest snapshot testing is simultaneously the most misused testing feature in the React ecosystem and genuinely useful when applied correctly. Teams either avoid it entirely (too fragile) or over-use it (snapshot everything and update blindly). Neither is right. This guide covers how snapshot testing actually works, when it provides real
Testing
Chromatic is a visual testing tool built specifically for Storybook. While Percy and Applitools operate at the page level (snapshot a URL), Chromatic operates at the component level — it captures every story in your Storybook and compares them against approved baselines. This makes Chromatic the right choice for design system
Testing
React Testing Library (RTL) has become the standard for testing React components. It replaced Enzyme as the go-to tool because it tests behavior, not implementation. If you're still testing internal state or calling component methods directly, you're doing it wrong — and RTL is here to fix
Testing
Storybook started as a UI development tool — a sandbox where you could render components in isolation and iterate on them without spinning up your whole application. That's still what most people use it for. But since Storybook 7, it has grown into a legitimate component testing platform. You