https://github.com/mustaddon/contravariancedependencyinjection

Contravariant and Covariant injection for Microsoft.Extensions.DependencyInjection
https://github.com/mustaddon/contravariancedependencyinjection

contravariance contravariance-dependency-injection contravariance-di contravariant covariance covariant dependency-injection dependency-injection-container proxy-pattern service-collection service-provider virtual-proxy

Last synced: 29 days ago
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Contravariant and Covariant injection for Microsoft.Extensions.DependencyInjection

• Host: GitHub
• URL: https://github.com/mustaddon/contravariancedependencyinjection
• Owner: mustaddon
• License: mit
• Created: 2024-10-21T13:02:37.000Z (3 months ago)
• Default Branch: main
• Last Pushed: 2024-11-20T07:22:43.000Z (2 months ago)
• Last Synced: 2024-12-16T18:13:03.106Z (about 1 month ago)
• Topics: contravariance, contravariance-dependency-injection, contravariance-di, contravariant, covariance, covariant, dependency-injection, dependency-injection-container, proxy-pattern, service-collection, service-provider, virtual-proxy
• Language: C#
• Homepage:
• Size: 515 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# ContravarianceDependencyInjection [![NuGet version](https://badge.fury.io/nu/ContravarianceDependencyInjection.svg?7)](http://badge.fury.io/nu/ContravarianceDependencyInjection)

Contravariant and Covariant injection for Microsoft.Extensions.DependencyInjection using the [Proxy pattern](https://en.wikipedia.org/wiki/Proxy_pattern).

### Example

```C#

interface IExampleContravariant

{

    object? MyMethod(T request);

}

```

```C#

var services = new ServiceCollection()

    .AddTransient, ExampleService>()

    .AddTransient, ExampleService>()

    .AddTransient, ExampleService>()

    // REQUIRED: Adds contravariance injection for registred services IExampleContravariant

    .AddContravariance(typeof(IExampleContravariant<>), SearchStrategy.MaxCloser)

    .BuildServiceProvider();

// inheritance example contracts

// ContractBase -> ContractA -> ContractAB -> ContractABC

// ContractBase -> ContractB

// IExampleContravariant is not registered,

// IExampleContravariant is invoked instead 

Console.WriteLine("  Result: " +

    services.GetRequiredService>()

        .MyMethod(new ContractABC()));

// IExampleContravariant is not registered,

// IExampleContravariant is invoked instead 

Console.WriteLine("  Result: " +

    services.GetRequiredService>()

        .MyMethod(new ContractB()));

```

[Program.cs](https://github.com/mustaddon/ContravarianceDependencyInjection/blob/main/Example/Program.cs)

### Concept

[](https://app.dgrm.net/?u=https://raw.githubusercontent.com/mustaddon/ContravarianceDependencyInjection/master/dgrm.png)