fix: vitest compatibility — ESM entrypoint and framework-agnostic matcher

[quantizor]

Summary

• Fixes vitest entrypoint fails: jest-styled-components/vitest uses require('vitest') which is ESM-only #458: Convert vitest/index.js to ESM via scoped vitest/package.json with "type": "module", using createRequire to bridge to CJS source modules. The previous CJS require('vitest') threw because Vitest v4 is ESM-only.
• Fixes Usage of expect in matcherTest breaks under Vitest without injected globals #459: Replace expect.stringMatching() / expect().toEqual() in matcherTest with plain JS — RegExp.test(), asymmetricMatch() protocol, and strict equality. This removes the dependency on any test framework's global expect, so toHaveStyleRule works in Vitest without globals: true.
• Add jest-environment-jsdom@27 as explicit dev dep for Node 24 compatibility
• Pin http-proxy-agent override to ^7.0.0 (v8 is ESM-only, breaks Jest 27's CJS require)
• Add pnpm workspace with Vitest test suite (globals: false) covering matcher and serializer

[changeset-bot]

🦋 Changeset detected

Latest commit: 92a015e

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[quantizor]

Testable via npm i jest-styled-components@test

[Copilot]

Pull request overview

Fixes Vitest v4 integration by making the /vitest entrypoint ESM-compatible and removing hard dependency on a global expect inside matcher logic, plus adds a pnpm workspace-based Vitest test suite to validate behavior with globals: false.

Changes:

• Convert vitest/index.js to ESM (scoped "type": "module") while bridging to existing CJS source via createRequire.
• Refactor matcherTest to use framework-agnostic matching (RegExp/asymmetricMatch/strict equality) instead of expect.*.
• Add a pnpm workspace + Vitest tests (and snapshots) to exercise matcher/serializer under Vitest without globals; adjust tooling deps/overrides for Node 24 + Jest 27.

Reviewed changes

Copilot reviewed 14 out of 15 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
vitest/package.json	Marks the /vitest entrypoint directory as ESM via "type": "module".
vitest/index.js	Switches Vitest entrypoint to ESM imports and re-exports utilities for Vitest setup.
src/utils.js	Makes matcherTest independent of framework expect, enabling Vitest without globals.
test/vitest/vitest.config.js	Adds Vitest config (jsdom, globals: false) for the new test workspace.
test/vitest/toHaveStyleRule.test.jsx	Adds Vitest coverage for toHaveStyleRule across common cases (regex/asymmetric/etc.).
test/vitest/styleSheetSerializer.test.jsx	Adds Vitest coverage for serializer snapshot output.
test/vitest/__snapshots__/styleSheetSerializer.test.jsx.snap	Commits Vitest snapshot outputs for serializer tests.
test/vitest/package.json	Defines a workspace package to run Vitest tests against the local workspace build.
pnpm-workspace.yaml	Declares the test/vitest workspace package for pnpm.
package.json	Adds test:vitest, ignores Vitest tests in Jest, adds jest-environment-jsdom, updates override, bumps version.
pnpm-lock.yaml	Locks new workspace deps and adjusts http-proxy-agent override + jest-environment-jsdom.
test/setup.js	Suppresses some console.error noise during Jest tests.
.nvmrc	Bumps CI/local Node version target to v24.
.changeset/vitest-compat.md	Adds changeset describing Vitest compatibility fix.

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

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