Support Vitest 4 in `@cloudflare/vitest-pool-workers`

[penalosa]

Fixes https://github.com/cloudflare/workers-sdk/issues/11064 Fixes https://github.com/cloudflare/workers-sdk/issues/8369 (defineWorkersConfig is removed) Fixes https://github.com/cloudflare/workers-sdk/issues/7795 (everything is now encapsulated in a plugin, and so this type of configuration problem is impossible) Fixes https://github.com/cloudflare/workers-sdk/issues/7339 (we no longer recommend importing env from cloudflare:test. Instead, import env from cloudflare:workers and use withEnv to override the value: https://developers.cloudflare.com/workers/runtime-apis/bindings/#overriding-env-values) Fixes https://github.com/cloudflare/workers-sdk/issues/10260 (tests added to verify the mentioned libraries can be imported)

This a major breaking change to the @cloudflare/vitest-pool-workers integration in order to support Vitest v4. Along with supporting Vitest v4 (and dropping support for Vitest v2 and v3), we've made a number of changes that may require changes to your tests. Our aim has been to improve stability & the foundations of @cloudflare/vitest-pool-workers as we move towards a v1 release of the package.

We've made a codemod to make the migration easier: wrangler codemod vitest-pool-v3-to-v4, which will make the required changes to your config file.

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• Tests
  • [ ] Tests included/updated
  • [ ] Tests not necessary because:
• Public documentation
  • [ ] Cloudflare docs PR(s):
  • [ ] Documentation not necessary because:
• Wrangler V3 Backport
  • [ ] Wrangler PR:
  • [ ] Not necessary because:

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[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: 704466b464059b943a8c0ead34745cab175e96b6

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commit: 704466b

[claude[bot]]

Claude finished @penalosa's task —— View job

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Changeset Review

Reviewing changeset files...

• [x] Read changeset guidelines
• [x] Review .changeset/many-fishes-raise.md
• [x] Review .changeset/auth-token-command.md
• [x] Check for cute animal image
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• [x] Check changelog quality
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✅ All changesets look good

Both changeset files pass validation:

.changeset/many-fishes-raise.md (@cloudflare/vitest-pool-workers: minor)

• ✅ Version type: Correct (minor for new feature with breaking changes to experimental/pre-1.0 package)
• ✅ Changelog quality: Comprehensive description with migration guide and codemod usage example
• ✅ Markdown formatting: No forbidden h1/h2/h3 headers

.changeset/auth-token-command.md (wrangler: minor)

• ✅ Version type: Correct (minor for new CLI command)
• ✅ Changelog quality: Clear description with multiple usage examples
• ✅ Markdown formatting: No forbidden h1/h2/h3 headers
• ✅ No major version bump for wrangler (which would be forbidden)

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Cute Animal Report: This is a mysterious orange circle. Very round. Perfect form. Possibly a celestial body or a very shy hamster. Needs more pixels for proper identification. 7/10 for trying.