Jest remains the testing workhorse for TypeScript projects with 70% market share for good reason. The ts-jest integration gives you full type safety, and the ecosystem is unmatched: React Testing Library, snapshot testing, built-in coverage, and mature tooling that just works. Setup is straightforward with `npx ts-jest config:init`, and you get everything in one package instead of assembling pieces. If you're working on an existing React or Node.js codebase, this is likely already there. The mocking can feel verbose compared to newer frameworks, but the tradeoff is stability and Stack Overflow answers for every edge case you'll hit.
npx skills add https://github.com/bobmatnyc/claude-mpm-skills --skill jest-typescript