Recode

RECODE.video.1.-.Made.with.Clipchamp.2.mp4

Developer-first syntax drills with instant feedback, playlists, and a focused editor experience. Built to emphasize clean architecture, SOLID, DRY, and test coverage across unit, integration, and E2E layers.

Stack

• Backend: FastAPI + SQLModel + SQLite
• Frontend: React + Vite + Tailwind + Framer Motion
• Mobile: Flutter (Android + iOS)
• Tests: Pytest (unit/integration), Vitest (frontend unit), Playwright (e2e)
• Validation: Executes user code against expected outputs per language (no sandbox)

Project Layout

• backend/: API, domain, services, repositories, seed data
• frontend/: React app
• mobile/: Flutter app (Android + iOS)
• e2e/: Playwright tests

Prerequisites

• Python 3.11+
• Node.js 18+
• npm 9+
• Language runtimes for validation (install what you want to practice):
  • Python (uses current interpreter)
  • JavaScript (Node.js)
  • TypeScript (ts-node or tsc + Node.js)
  • Java (javac + java)
  • C++ (g++)
  • C# (dotnet SDK or csc + runtime)
  • Go (go)
  • Rust (rustc)
  • SQL (sqlite3 CLI)

Setup and Run Locally

Backend

cd backend
python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
uvicorn app.main:app --reload

The API will run on http://localhost:8000. A local SQLite database is created at backend/app.db and seeded on startup.

Frontend

cd frontend
npm install
npm run dev

The UI will run on http://localhost:5173 and will call the backend at http://localhost:8000 by default.

To customize the API URL:

VITE_API_URL=http://localhost:8000 npm run dev

Mobile (Flutter)

cd mobile
flutter pub get

Start the backend in a separate terminal (see Backend above).

If you need to (re)generate the platform folders:

cd mobile
flutter create --platforms=android,ios .

Run on an Android emulator

flutter emulators
flutter emulators --launch <emulator_id>
flutter run --dart-define=API_URL=http://10.0.2.2:8000

Run on the iOS simulator

open -a Simulator
flutter run --dart-define=API_URL=http://localhost:8000

Run on a real device (Android or iOS)

1. Connect the device (USB) and ensure it appears in flutter devices.
2. Use your machine's LAN IP for the API URL:

flutter run --dart-define=API_URL=http://<your-machine-ip>:8000

Notes:

• Android emulators cannot reach localhost on your host; use 10.0.2.2 instead.
• If you run into cleartext HTTP restrictions, enable HTTP for local dev:
  • Android: set android:usesCleartextTraffic="true" in android/app/src/main/AndroidManifest.xml.
  • iOS: set NSAppTransportSecurity -> NSAllowsArbitraryLoads to YES in ios/Runner/Info.plist.
• iOS builds require macOS + Xcode.

Quickstart (Two Terminals)

Terminal 1:

cd backend
python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
uvicorn app.main:app --reload

Terminal 2:

cd frontend
npm install
npm run dev

Tests

Backend unit + integration

cd backend
pytest

Frontend unit

cd frontend
npm run test

End-to-end

Start backend + frontend in separate terminals, then:

cd e2e
npm install
npm run test

Mobile (Flutter)

cd mobile
flutter test
flutter test integration_test

Notes

• Data is seeded automatically on backend startup.
• Validation runs code using local runtimes and compares output to lesson expectations.
• To refresh lesson content after seed changes, delete backend/app.db and restart the backend.
• To reset timing stats (attempts + best scores):

  sqlite3 backend/app.db "DELETE FROM attempt; DELETE FROM bestscore;"