Akka Net Testing Patterns

What it does

This skill provides tools and patterns for writing tests for Akka.NET actors, specifically focusing on unit testing and quality assurance workflows. It offers two primary approaches: Akka.Hosting.TestKit (recommended for most use cases) and the traditional Akka.TestKit. The skill helps with verifying actor interactions, message flows, supervision, lifecycle management, mocking dependencies, cluster sharding behavior, and state recovery in Akka.NET applications.

When to use it

• Writing unit tests for Akka.NET actors.
• Testing persistent actors that utilize event sourcing.
• Verifying how actors interact with each other and the messages they exchange.
• Testing actor supervision and lifecycle management.
• Mocking external dependencies within actor tests.
• When building modern .NET applications using Microsoft.Extensions.DependencyInjection and Akka.Hosting.

Key capabilities

• Akka.Hosting.TestKit: Provides native dependency injection support for testing, allowing service overrides with fakes.
• Configuration Parity: Enables the use of the same extension methods in tests as are used in production environments.
• Type-Safe Actor Registry: Facilitates retrieving actor references in a type-safe manner.
• Traditional Akka.TestKit: Suitable for contributing to the Akka.NET core library, working with legacy systems, or when dependency injection is not utilized.
• Reference Materials: Includes example code (examples.md) and guidance on anti-patterns and CI/CD integration (anti-patterns-and-reference.md).

Example prompts

Here are a few examples of how you might instruct an agent using this skill:

• "Write a unit test for my Akka.NET actor, mocking the database connection."
• "Show me how to configure Akka.Hosting.TestKit for testing with dependency injection."
• "Give me an example of verifying message flow between two actors in Akka.NET using the TestKit."

Tips & gotchas

• NuGet Packages: Requires installing specific NuGet packages, including Akka.Hosting.TestKit, a test framework like xUnit, and FluentAssertions for assertions.
• Akka.Hosting.TestKit Best Practices: Focus on overriding services in the ConfigureServices() method and configuring actors using ConfigureAkka(). Avoid creating custom base classes; favor method overrides instead.