Train Schedule

A full-stack train schedule application built as a monorepo. The backend provides a REST API with JWT authentication and role-based access control; the frontend is a React Native mobile app (iOS & Android) built with Expo.

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Tech Stack

Backend

• NestJS — Node.js framework
• PostgreSQL + TypeORM — database and ORM
• JWT + Passport — authentication & authorization
• Swagger — auto-generated API documentation
• bcryptjs — password hashing

Frontend

• React Native + Expo (SDK 54) — mobile app
• Expo Router — file-based navigation
• React Query — server state management
• Zustand — global UI state (filters, etc.)
• React Hook Form — form management & validation
• Unistyles — theming & styling (light / dark mode)
• Axios — HTTP client

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Project Structure

train-schedule/
├── backend/          # NestJS REST API
│   └── src/
│       ├── auth/         # JWT auth, guards, strategies
│       ├── trains/       # Train CRUD module
│       ├── favorites/    # Favorites module
│       ├── users/        # User entity
│       └── seed.ts       # Database seeder
└── frontend/         # Expo React Native app
    └── src/
        ├── api/          # Axios API clients
        ├── app/          # Expo Router screens
        │   ├── (auth)/   # Login, Register
        │   └── (tabs)/   # Home, Favorites, Admin
        ├── components/   # Shared UI components
        ├── hooks/        # Custom React hooks
        ├── store/        # Zustand stores
        └── types/        # TypeScript type definitions

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Prerequisites

• Node.js v20+
• Yarn v1 (classic)
• PostgreSQL 14+
• Xcode (for iOS simulator) or Android Studio (for Android emulator)
• Expo Go app on a physical device (optional)

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Setup

1. Backend

Install dependencies

cd backend
yarn install

Configure environment variables

Copy the example file and fill in your values:

cp .env.example .env

.env variables:

Variable	Default	Description
DB_HOST	localhost	PostgreSQL host
DB_PORT	5432	PostgreSQL port
DB_USERNAME	postgres	PostgreSQL username
DB_PASSWORD	postgres	PostgreSQL password
DB_NAME	train_schedule	PostgreSQL database name
PORT	3000	HTTP port the API listens on
JWT_SECRET	secret	Secret used to sign JWT tokens

Important: Change JWT_SECRET to a strong random value in any non-local environment.

Create the database

psql -U postgres -c "CREATE DATABASE train_schedule;"

Seed the database

Populates 5 sample trains and 2 test users:

yarn seed

Test users created by the seeder:

Email	Password	Role
admin@example.com	admin123	admin
user@example.com	user123	user

Start the development server

yarn start:dev

The API will be available at http://localhost:3000.
Swagger UI is available at http://localhost:3000/api.

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2. Frontend

Install dependencies

cd frontend
yarn install

Configure the API URL

Copy the example file and fill in your values:

cp .env.example .env

.env variables:

Variable	Default	Description
EXPO_PUBLIC_API_URL	http://localhost:3000	Base URL of the REST API

• For a physical device, replace localhost with your machine's local IP (e.g. http://192.168.1.100:3000).
• For an Android emulator, use http://10.0.2.2:3000.
• For an iOS simulator, localhost works as-is.

Generate native project folders

Before running on a simulator or device for the first time, generate the ios/ and android/ native folders:

npx expo prebuild

Re-run this command whenever you add a new native dependency or change app.json settings that affect native code. Use --clean to fully regenerate the folders from scratch.

Start the app

# Expo development server
yarn start

# Run directly on iOS simulator
yarn ios

# Run directly on Android emulator
yarn android

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Features

User

• Register and log in with email & password
• Browse and search the full train schedule
• Filter trains by status (On Time / Delayed / Cancelled)
• Save favourite trains and view them on a dedicated screen
• Toggle light / dark theme

Admin

• All user features
• Add, edit, and delete trains from the Admin dashboard

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API Overview

All endpoints are documented interactively via Swagger at http://localhost:3000/api.

Method	Path	Auth	Description
POST	/auth/register	Public	Register a new user, returns JWT
POST	/auth/login	Public	Login, returns JWT
GET	/auth/profile	JWT	Get current user profile
GET	/trains	JWT	List trains (with filters)
POST	/trains	JWT + Admin	Create a train
PATCH	/trains/:id	JWT + Admin	Update a train
DELETE	/trains/:id	JWT + Admin	Delete a train
GET	/favorites	JWT	Get current user's favorites
POST	/favorites/:trainId	JWT	Add train to favorites
DELETE	/favorites/:trainId	JWT	Remove train from favorites

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Available Scripts

Backend (/backend)

Command	Description
yarn start:dev	Start in watch mode (development)
yarn start:prod	Start the compiled production build
yarn build	Compile TypeScript to dist/
yarn seed	Seed the database with sample data
yarn test	Run unit tests
yarn test:e2e	Run end-to-end tests
yarn lint	Lint & auto-fix source files

Frontend (/frontend)

Command	Description
yarn start	Start the Expo development server
yarn ios	Run on iOS simulator
yarn android	Run on Android emulator
yarn lint	Lint & auto-fix source files