Open source
We build the testing tools we use on client projects — and publish them for everyone. They are free, open source and in active use.
playwright-repl & Dramaturg
Interactive browser automation with record & replay. Type simple commands like click "Submit" or fill "Email" "a@b.c", see the result immediately, and record your clicks into a reusable script.
- CLI — browser automation from your terminal, no code required
- Dramaturg — the same, as a Chrome side panel with console, recorder and debugger
- VS Code extension — an interactive Playwright REPL inside your editor
- MCP server — lets AI assistants drive a real browser
Used for: writing and debugging Playwright tests faster.
GitHub · npm · Chrome Web Store (Dramaturg) · VS Code Marketplace
nextcov
Code coverage for Next.js apps from Playwright end-to-end tests — including React Server Components, which standard coverage tools miss.
Used for: seeing what your end-to-end tests actually cover.
GitHub · npm · Read the series
msw-terrarium
Isolated, stateful API mocks for parallel Playwright tests. Each test gets its own "bucket" of mock data, so tests running at the same time never interfere.
Used for: fast, reliable tests that run in parallel.
GitHub · npm · Example app
vitest-coverage-merge
Merge Vitest coverage from unit tests (jsdom) and browser component tests into one accurate report — handling the statement-count differences between the two environments.
Used for: one coverage number across all your Vitest tests.
GitHub · npm · Read the article
Earlier projects
- endpoint-response-override — override the responses of an Express or json-server backend on the fly, to test how the frontend handles different server responses, including Next.js server-side rendering. GitHub · npm · Related article
More projects on GitHub.
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