[ulissesferreira]

Summary

Scaffolds a new @metamask/snaps-vitest package in the monorepo. This is the first PR in a stack; the full implementation lands in the follow-up PR.

packages/snaps-vitest/
├── package.json       # dual ESM/CJS exports for index, environment, setup, config
├── tsconfig.json      # references snaps-controllers, snaps-sdk, snaps-simulation, snaps-utils
├── tsconfig.build.json
├── vitest.config.mts
├── src/
│   ├── index.ts
│   ├── config.ts      # snapsVitestPreset and getSnapsVitestConfig
│   └── config.test.ts
├── CHANGELOG.md
├── LICENSE
└── README.md

Wiring changes:

 tsconfig.json            # add package project reference
 tsconfig.build.json      # add package build reference
 eslint.config.mjs        # treat package src as Node.js source
 yarn.config.cjs          # allow Vitest test scripts instead of the shared Jest scripts
 README.md                # generated package list / dependency graph
 yarn.lock

The package supports Vitest ^3.1.1, matching the version already used in the monorepo. getSnapsVitestConfig sets the production Snaps JSX runtime through Vite's esbuild options.

Evidence

• Before: no @metamask/snaps-vitest workspace.
  After: yarn workspace @metamask/snaps-vitest run build, lint, and test pass; yarn constraints and yarn lint:tsconfig pass.

Merge Danger

Door: two-way

Blast Radius: low

New workspace only. Build, lint, and test scripts are additive; the only shared-file changes are project references and the Vitest test-script exception.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.69%. Comparing base (20c55c4) to head (7ee7176).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4174   +/-   ##
=======================================
  Coverage   98.69%   98.69%           
=======================================
  Files         429      429           
  Lines       12533    12533           
  Branches     1986     1986           
=======================================
  Hits        12369    12369           
  Misses        164      164           

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.