Grove

Simple Swift Dependency Injection Container. Somewhat like a grove is a group of trees, Grove's container represents a group of dependencies, and it provides you with tools to easily manage them.

Description

Grove is a super simple and lightweight Dependency Injection library available for Swift. It's designed to help you manage a group of dependencies in a container, and easily resolve them when needed, thus helping make your project more modular, testable, and maintainable.

Features

• Lightweight and Focused - Specifically responsible for dealing with dependency injection.
• Swift-native Design - Grove feels natural and intuitive for Swift developers.
• Scoped Instances - Capable of setting dependencies' lifetime scope (as singleton or transient).
• Thread-safe - Grove maintains thread-safety when registering and resolving dependencies.
• Simple - With Grove's @Resolve property wrapper, usage is cleaner and super easy.

Installation

Grove is available through the Swift Package Manager. To install it, simply add the following line to your Package.swift file:

dependencies: [
    .package(url: "https://github.com/willowtreeapps/grove.git", from: "1.1.2")
]

Usage

Grove simplifies dependency registration and resolving. Here's an example:

Registration

let container = Grove.defaultContainer // You can use the default container or create your own

// Register specifying a type to use for resolution
container.register(as: NASARepositoryProtocol.self, NASARepository())

// Register a reference type dependency as a singleton 
container.register(JSONEncoder())

// or with a transient lifetime
container.register(scope: .transient, JSONEncoder())

// Register a value type dependency (an enum for example)
container.register(DeploymentEnvironment.production)

Resolution

// Later in your code, you can resolve the dependency
let jsonEncoder: JSONEncoder = container.resolve()

// Alternatively, you can use the @Resolve property wrapper:
@Resolve(JSONEncoder.self) var jsonEncoder

// Value types are resolved the same way (here deploymentEnvironment would be .production)
@Resolve(DeploymentEnvironment.self) var deploymentEnvironment

Using the included registrar

This shows how you can set up a registrar class both for production and for unit tests and SwiftUI previews:

import Grove

@main
struct YourApp: App {

    init() {
        GroveRegistrar.register(
            /// Registers dependencies that will be used normally by the app
            baseDependencies: { container in
                container.register(as: Environment.self, Environment.production)
                container.register(as: NASARepositoryProtocol.self, NASARepository())
            },
            /// Registers overrides to be used by the app during development (RUNNING_IN_DEVELOPMENT_MODE environment variable)
            developmentOverrides: { container in
                container.register(as: Environment.self, Environment.local)
                container.register(as: NASARepositoryProtocol.self, MockNASARepository())
            },
            /// Registers overrides to be used by the app during unit tests and swiftui previews 
            unitTestOverrides: { container in
                container.register(as: Environment.self, Environment.local)
                container.register(as: NASARepositoryProtocol.self, MockNASARepository())
            },
            /// Registers dependencies to be used by the app during UI automation tests
            uiAutomationOverrides: { container in
                container.register(as: Environment.self, Environment.mockService)
            }
        )
    }
}

Contributing

Contributions are immensely appreciated. Feel free to submit pull requests or to create issues to discuss any potential bugs or improvements.

Author

Grove was created by @rafcabezas at WillowTree, Inc.

License

Grove is available under the MIT license.