DayOne - Daily Habit Streak Tracker

<img src="src/assets/brand/launch-icon.png" alt="DayOne Logo" width="200"/> Build lasting habits, one day at a time <a href="#features">Features</a> • <a href="#tech-stack">Tech Stack</a> • <a href="#getting-started">Getting Started</a> • <a href="#architecture">Architecture</a> • <a href="#testing">Testing</a> • <a href="#contributing">Contributing</a>

📱 About

DayOne is a mobile application designed to help users build and maintain daily habits through a streak-based tracking system. The app focuses on simplicity and motivation, making it easy for users to track their progress and maintain consistency in their daily routines.

📸 Screenshots

<img src="screenshots/dashboard-screen.png" alt="Dashboard Screen" width="250"/> <img src="screenshots/new-habit-screen.png" alt="New Habit Screen" width="250"/> <img src="screenshots/streak-check-screen.png" alt="Streak Check Screen" width="250"/> Dashboard • Create New Habit • Daily Check-in

✨ Features

📊 Habit Management: Create, edit, and organize your daily habits
🔥 Streak Tracking: Visual streak counters to keep you motivated
📅 Daily Check-ins: Mark habits as complete with a simple tap
🎯 Goal Setting: Set target duration for your habits
🔍 Search & Filter: Quickly find and manage your habits
🎨 Custom Icons: Personalize your habits with icons
📈 Progress Visualization: Track your longest and current streaks
💾 Offline Support: All data stored locally for privacy and offline access

🚀 Tech Stack

Core Technologies

React Native (0.81.4) - Cross-platform mobile development
Expo (~54.0.13) - Development platform and tooling
TypeScript (~5.8.3) - Type-safe development
Expo Router (~5.0.7) - File-based navigation

State Management & Data

React Query (TanStack Query v5) - Server state management
React Hook Form (7.56.4) - Form management with validation
MMKV (3.3.3) - Fast, encrypted key-value storage
Zod (3.23.8) - Schema validation

UI & Styling

Shopify Restyle (2.4.5) - Type-safe theming system
React Native Reanimated (4.1.3) - Smooth animations
Phosphor React Native (2.2.1) - Icon library
React Native SVG (15.12.0) - SVG support

Development Tools

Jest & Jest Expo - Testing framework
React Native Testing Library - Component testing
Husky - Git hooks for code quality
ESLint & Prettier - Code formatting and linting
Babel Module Resolver - Path aliasing

🏁 Getting Started

Prerequisites

Node.js (v18 or higher)
npm, yarn, or bun package manager
Expo CLI
iOS Simulator (Mac only) or Android Emulator

Installation

Clone the repository

git clone https://github.com/yourusername/DayOne.git
cd DayOne

Install dependencies

# Using npm
npm install

# Using yarn
yarn install

# Using bun
bun install

Start the development server

npm start
# or
yarn start
# or
bun start

Run on your device/emulator

# For iOS
npm run ios

# For Android
npm run android

# For Web
npm run web

🏗️ Architecture

Project Structure

DayOne/
├── app/                    # Expo Router navigation
│   ├── (app)/             # Authenticated app routes
│   ├── _layout.tsx        # Root layout
│   └── index.tsx          # Entry point
├── src/
│   ├── assets/            # Images, fonts, and static files
│   ├── infra/             # Infrastructure layer
│   │   ├── adapters/      # External service adapters
│   │   ├── config/        # Configuration files
│   │   ├── repository/    # Data persistence layer
│   │   └── types/         # Infrastructure types
│   ├── modules/           # Feature modules
│   │   ├── habit/         # Habit management module
│   │   │   ├── domain/    # Business logic and entities
│   │   │   ├── screens/   # UI components
│   │   │   └── __tests__/ # Module tests
│   │   └── streak/        # Streak tracking module
│   │       ├── domain/    # Business logic and entities
│   │       └── __tests__/ # Module tests
│   ├── shared/            # Shared components and utilities
│   │   ├── helpers/       # Utility functions
│   │   ├── hooks/         # Custom React hooks
│   │   ├── layout/        # Layout components
│   │   ├── navigation/    # Navigation utilities
│   │   ├── services/      # Shared services
│   │   └── ui/            # UI components library
│   ├── styles/            # Global styles and themes
│   └── test/              # Test utilities and setup

Design Patterns

Domain-Driven Design: Clear separation between domain logic and infrastructure
Use Case Pattern: Business logic encapsulated in service classes
Repository Pattern: Abstraction layer for data persistence
Dependency Injection: Loose coupling between modules
Component Composition: Reusable UI components with consistent APIs

🧪 Testing

Running Tests

# Run all tests
npm test

# Watch mode for development
npm run test:watch

# Generate coverage report
npm run test:coverage

Test Structure

The project includes comprehensive testing at multiple levels:

Unit Tests

Service Layer: Testing business logic in isolation
Domain Models: Validating entity behaviors
Utilities: Testing helper functions

Integration Tests

Screen Flows: Testing complete user journeys
Data Persistence: Verifying repository operations
Navigation: Testing routing and deep linking

Test Files Organization

__tests__/
├── *.integration.test.ts   # Integration tests for screens
└── *.service.test.ts        # Unit tests for services

Pre-commit Hooks

Tests automatically run before each commit via Husky to ensure code quality.

🤝 Contributing

We welcome contributions to DayOne! Here's how you can help:

Development Process

Fork the repository and create your branch from main
Make your changes following our coding standards
Write/update tests for your changes
Ensure all tests pass with npm test
Submit a pull request with a clear description

Coding Standards

TypeScript: Use proper types, avoid any
Components: Functional components with hooks
Naming: Use descriptive, consistent naming
Comments: Document complex logic
Testing: Maintain or improve test coverage

Commit Convention

Follow conventional commits format:

type(scope): description

[optional body]

[optional footer]

Types: feat, fix, docs, style, refactor, test, chore

Bug Reports

Please use GitHub Issues to report bugs. Include:

Device and OS version
Steps to reproduce
Expected vs actual behavior
Screenshots if applicable

Feature Requests

We'd love to hear your ideas! Please submit feature requests as GitHub Issues with:

Clear use case description
Proposed solution (optional)
Alternative solutions considered

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

Built with Expo
Icons by Phosphor Icons
Type-safe theming with Shopify Restyle

📞 Contact

GitHub Issues: For bug reports and feature requests
Discussions: For questions and community support

Made with ❤️ by the DayOne Team

DayOne

Install / Use

README