Storybook is an open-source tool for developing UI components in isolation for React, Vue, and Angular applications. Readers can learn about component-driven development, UI testing, and design systems. With documentation, tutorials, and community contributions, Storybook offers  guidance and tools for building modular and reusable UI components.

Storybook

Storybook 9 introduces comprehensive frontend test coverage tracking that measures how much component code is exercised by stories. The new workflow allows developers to run interaction, accessibility, and visual tests with a single command, identify untested components and code branches, and quickly fill coverage gaps by generating new stories. This approach provides high coverage of UI states while being faster and more reliable than end-to-end tests, though it complements rather than replaces them for full application testing.

Frontend test coverage with Storybook 9

Where Storybook fits in your frontend testing strategy