[Tracking]: Test-Related Package Consolidation

[valentinpalkovic]

This milestone aims to consolidate test-related packages into a unified @storybook/addon-test package. The goal is to simplify testing workflows and ensure all relevant test utilities are maintained under a single addon. The work requires package migrations, updates to CLI behavior, automigrations, and comprehensive documentation.

Items:

1. Promote @storybook/experimental-addon-test to stable @storybook/addon-test

• Rename and restructure @storybook/experimental-addon-test as @storybook/addon-test
  • Update package.json metadata (name, version, description) in the package
  • Ensure stable API exposure for the new @storybook/addon-test package
  • Remove "experimental" labels and update all internal references in the codebase

2. Merge test-related packages into @storybook/addon-test

• Remove @storybook/addon-interactions
  • Make sure its not referenced anywhere and change all references to the new package instead
  • Make sure automigrations or init scripts don't install @storybook/addon-interactions anymore
  • Remove @storybook/addon-interactions docs (@jonniebigodes)
  • Deprecating package on npm
• Merge @storybook/addon-actions
  • Move the implementation actions addon into @storybook/addon-test
  • Update all references in the Storybook codebase (and in user-facing guides) from addon-actions to the new unified addon-test
  • Remove the @storybook/addon-actions package from the monorepo (ensure no leftover references)
  • Create docs page for code/addons/actions/ADVANCED.md if not already happened (@jonniebigodes)
  • Test https://storybook.js.org/docs/essentials/actions#action-event-handlers separately
  • Deprecating package on npm
• Merge @storybook/instrumenter
  • Transfer instrumentation logic from @storybook/instrumenter into @storybook/addon-test
  • Update all related import paths and documentation in the codebase to use @storybook/addon-test for instrumentation
  • Update /~https://github.com/storybookjs/storybook/blob/valentin/test-package-consolidation/code/addons/essentials/src/preset.ts#L11 (@jonniebigodes)
  • Remove the @storybook/instrumenter package from the monorepo after a successful merge
  • Deprecating package on npm
• Merge @storybook/test
  • Take a look at /~https://github.com/storybookjs/storybook/blob/next/code/core/src/preview-api/modules/store/csf/prepareStory.ts#L58-L60 workaround. Can be removed

3. Update CLI to reflect new Test addon behavior

• Modify the Storybook CLI to include @storybook/addon-test when "Testing" is selected for all new Storybook projects
  • Make sure that template stories use @storybook/addon-test

4. Rewrite post-install script to ask for Test Module usage

• Rewrite post-install script to allow "addon-interactions" mode

5. Automigration & Documentation Updates

• Write an automigration script to transition existing projects to the new addon
  • Automatically replace old imports (@storybook/test, @storybook/addon-actions, etc.) with @storybook/addon-test in user codebases
  • Remove now-redundant dependencies (@storybook/test, @storybook/addon-interactions, @storybook/addon-actions, @storybook/instrumenter, @storybook/experimental-addon-test) from users’ package.json
  • Verify that the automigration covers all common use cases and edge cases (run it against a sample of real projects if possible)
  • Automigration: Install @storybook/addon-test for the user if they had @storybook/addon-essentials
• Update Addon Kit to use @storybook/addon-test
• Update documentation & migration notes for Storybook 9
  • Provide a clear migration guide for users moving from Storybook 8.x to 9, highlighting the new @storybook/addon-test and the removal of the old packages
  • Document the new unified testing workflow and its benefits in the official docs (e.g., Guide for “Testing in Storybook 9”) (@jonniebigodes)
  • Update all relevant Storybook documentation sections (addons list, CLI docs, configuration guides) to reflect the consolidated test addon (@jonniebigodes)
• Point @storybook/addon-test readme to official documentation
• Remap /~https://github.com/storybookjs/storybook/blob/next/code/addons/test/src/vitest-plugin/index.ts#L298