React 19 + Web Components

An investigation lab that probes how React 19 handles web components: lifecycle, prop/attribute/event passing, stability under re-renders, nesting, performance, React Compiler interaction and SSR. Built for a Marmelab hackday (2026-07-24).

Prerequisites

• Node >= 24 (pnpm dev:ssr runs the TypeScript server entry directly through Node's built-in type stripping, with no separate build/transpile step)
• pnpm

Run it

• pnpm install
• pnpm dev → SPA lab at http://localhost:5173 (one route per experiment)
• COMPILER=on pnpm dev → same, with the native React Compiler (oxc-transform-react); check the header badge
• pnpm --filter lab build && pnpm --filter lab preview → production build on http://localhost:4173, for benchmarking /perf (prefix the build with COMPILER=on and/or PROFILE=on, the latter to keep the Profiler column)
• node lab/scripts/perf-bench.mjs --passes 3 → the whole /perf matrix (production, profiling and dev builds, compiler off and on) in headless Chrome and Firefox, printed as Markdown tables. Playwright isn't a lab dependency: point PLAYWRIGHT at its package if it isn't resolvable
• pnpm dev:ssr → SSR server at http://localhost:5199 (experiment 7)
• pnpm --filter corp-components build && pnpm --filter consumers dev → enterprise demo at http://localhost:5273 (the build step is required because dist/ is gitignored)

License

MIT, see LICENSE.