tifroz/tinytca

Overview

tinyTCA provides the core TCA concepts (composability + testability) using only Swift Concurrency, making it compatible with any platform that supports Swift 6.1+, including Android.

Key differences from Point-Free's TCA:

• ❌ No Combine dependency (uses AsyncStream and async/await)
• ❌ No ViewStore (use @Observable directly in SwiftUI)
• ❌ No macros (simpler, but more verbose)
• ✅ Full Android compatibility
• ✅ Same mental model and patterns
• ✅ Testable and composable reducers

Requirements

• Swift 6.1+
• Platforms: iOS 16+, macOS 13+, Android (via Swift SDK)

Core Components

1. Reducer Protocol

Pure functions that handle state mutations:

struct CounterReducer: Reducer {
  struct State: Equatable {
    var count: Int = 0
  }

  enum Action: Equatable {
    case increment
    case decrement
  }

  func reduce(into state: inout State, action: Action) -> Effect<Action> {
    switch action {
    case .increment:
      state.count += 1
      return .none
    case .decrement:
      state.count -= 1
      return .none
    }
  }
}

2. Store

Runtime that manages state and effects:

let store = Store(
  initialState: CounterReducer.State(),
  reducer: CounterReducer()
)

await store.send(.increment)
print(store.currentState.count) // 1

3. Effect

Async work using Swift Concurrency:

case .loadData:
  return .run { send in
    let data = try await apiClient.fetch()
    await send(.dataLoaded(data))
  }

4. TestStore

Deterministic testing:

let store = TestStore(
  initialState: CounterReducer.State(),
  reducer: CounterReducer()
)

await store.send(.increment) { state in
  state.count = 1
}

5. Dependencies (Optional)

Simple dependency injection:

extension DependencyValues {
  var apiClient: APIClient {
    get { self[APIClientKey.self] }
    set { self[APIClientKey.self] = newValue }
  }
}

Usage Example

See CounterExample.swift for a complete working example.

Testing

swift test

All 9 tests pass ✓

Building for Android

swift build --swift-sdk aarch64-unknown-linux-android28

Limitations

This is a minimal implementation focused on core patterns. It does not include:

• ViewStore (use SwiftUI's @Observable instead)
• Navigation helpers
• Debounce/throttle operators
• Macro support
• Comprehensive effect testing infrastructure

For a full-featured library, use Point-Free's TCA on Apple platforms.

License

MIT

Package Metadata

Repository: tifroz/tinytca

Default branch: main

README: README.md