kotsukotsu/CLAUDE.md

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

What This Is

A typing tutor app for a child (Leo), built with React 19 + TypeScript + Vite. Uses Bun as the package manager/runtime.

Commands

• bun run dev — start dev server
• bun run build — typecheck (tsc -b) then build for production
• bun run lint — ESLint
• bun run preview — serve production build locally

Architecture

Modes — The app has four tabs, each a top-level component rendered by App.tsx:

• LessonMode — structured lessons with progressive key introduction; lessons unlock sequentially (90%+ accuracy required)
• FreeMode — free typing practice using random quotes
• GameMode — arcade-style falling-words game with combo system and sound effects
• StatsView — charts (recharts) showing WPM/accuracy trends and per-key heatmaps

Core hook: useTypingEngine — shared typing logic used by LessonMode and FreeMode. Tracks cursor position, errors, WPM (updated every 500ms), per-key hit/miss stats, and fires onComplete when text is finished. GameMode has its own input handling since its mechanics differ (falling words, not linear text).

State: useStats — persists UserProgress (completed lessons, session history, game high score) to localStorage under key leo-typing-progress.

Sound: sounds.ts — all audio is synthesized via Web Audio API oscillators (no audio files). Exports: playKeyClick, playWordComplete, playCombo, playMiss, playGameOver.

Data files — src/data/lessons.ts (lesson definitions with word lists), src/data/quotes.ts (free mode texts), src/data/keyboard.ts (key-to-finger mapping for the visual keyboard).

Styling — CSS Modules (src/styles/*.module.css) plus a global stylesheet.