Regexle

Learn regex by guessing it — a Wordle-style daily puzzle game for regular expressions.

You're shown a set of strings the pattern must match and a set it must reject. Build a regex from token tiles; each guess is scored tile-by-tile (🟩 correct / 🟨 right token, wrong spot / ⬛ absent) and you get plain-English feedback on why it fails. Solve it in six guesses. A new puzzle every day, plus unlimited practice across three difficulty levels.

It runs entirely in the browser — the daily puzzle is generated deterministically from the date, and your stats live in localStorage.

Develop

npm install
npm run dev        # dev server on http://localhost:43210/

Command	What it does
npm run dev	Vite dev server (port 43210)
npm run build	Type-check + production build to dist/
npm run preview	Serve the built dist/
npm run test	Vitest (watch); npm run test:run for one run
npm run lint	ESLint
npm run format	Prettier write

Architecture

A small React SPA with a pure, deterministic game engine. Dependency direction is strict — ui → game → engine:

• src/engine/ — pure, seed-deterministic logic: puzzle generation, parsing/rendering, scoring, and the hint/diagnostic helpers. No React, no Date/Math.random. Unit-tested with Vitest.
• src/game/ — app glue: the daily/practice seeding (the only place randomness/clock is used) and localStorage persistence.
• src/ui/ — the React components (inline-styled).

See CLAUDE.md for a fuller tour.

Deployment

CI (.github/workflows/ci.yml) lints, tests, and builds on every push, and deploys to GitHub Pages from master. The site is served from the custom domain regexle.eldorado.io (public/CNAME), so vite.config.ts sets base: '/'. One-time setup: point a DNS CNAME record for regexle.eldorado.io at <org>.github.io, and set the custom domain in the repo's Pages settings.

Built with ♥ from LATAM by the El Dorado engineering team.