Coins

Features

• Market Overview: Browse cryptocurrencies sorted by market capitalization

• Search: Real-time search across the entire CoinGecko database with debounced API calls

• Filtering: Filter coins by top gainers, top losers, highest/lowest price

• Trending Coins: Horizontal scrollable cards showing top trending cryptocurrencies

• Coin Details: Detailed view with price, market statistics, and historical data

• Glass Morphism UI: Modern glass effect styling using native SwiftUI APIs

• Dark Mode Support: Semantic color usage for automatic light/dark mode adaptation

  
  

Architecture

The app follows the MVVM (Model-View-ViewModel) pattern with clear separation of concerns:

• Models: Coin, SearchResult - Data structures representing cryptocurrency information

• Views: SwiftUI views organized by feature (ContentView, CoinDetailView, reusable components)

• ViewModels: CoinsViewModel - Business logic and state management using Swift's @Observable macro

• Services: CoinService - Protocol-based networking layer for API interactions

• Utilities: PriceFormatter - Formatting utilities for prices and percentages

  
  

Technical Stack

• Language: Swift

• Framework: SwiftUI

• iOS Version: iOS 17+ (uses native @Observable and glassEffect APIs)

• API: CoinGecko API v3

• Architecture: MVVM with protocol-oriented design

• Testing: Unit tests for models, view models, and utilities

  
  

Project Structure

Coins/
├── App/
│   └── CoinsApp.swift          # App entry point
├── Core/
│   ├── Model/                  # Data models
│   ├── View/                   # SwiftUI views
│   │   ├── Components/         # Reusable UI components
│   │   └── ContentView.swift   # Main market view
│   ├── ViewModel/              # ViewModels
│   └── Utilities/              # Helper utilities
├── Services/
│   └── CoinService.swift       # API service layer
└── CoinTests/                  # Unit tests

API Integration

The app integrates with CoinGecko's free API:

• /coins/markets - Fetch market data for cryptocurrencies

• /search - Search for coins by name or symbol

• /coins/{id}/market_chart - Historical price, market cap, and volume data

All network requests use async/await with proper error handling and user-friendly error messages.

Key Components

• HeaderCard: Glass effect card displaying trending coin information

• CoinRowView: List item showing coin name, symbol, price, and 24h change

• CardView: Reusable card component for displaying key-value statistics

• CoinDetailView: Comprehensive detail view with market statistics

Testing

Unit tests are provided for:

• Model validation (CoinModelTests)

• ViewModel logic (CoinsViewModelTests)

• Price formatting (PriceFormatterTests)

• Coin data validation (CoinTests)

Requirements

• Xcode 15.4 or later

• iOS 17.0 or later

• Swift 5.9 or later