Microsoft.Extensions.Diagnostics.Testing

Hand-crafted fakes to make telemetry-related testing easier.

Install the package

From the command-line:

dotnet add package Microsoft.Extensions.Diagnostics.Testing

Or directly in the C# project file:

<ItemGroup> <PackageReference Include="Microsoft.Extensions.Diagnostics.Testing" Version="[CURRENTVERSION]" /> </ItemGroup>

Usage Example

Fake logging

These components enable faking logging services for testing purposes.

When using this package, you can register a fake logging provider by one of the following methods:

public static ILoggingBuilder AddFakeLogging(this ILoggingBuilder builder) public static ILoggingBuilder AddFakeLogging(this ILoggingBuilder builder, IConfigurationSection section) public static ILoggingBuilder AddFakeLogging(this ILoggingBuilder builder, Action<FakeLogCollectorOptions> configure)

You can also register fake logging in the service collection:

public static IServiceCollection AddFakeLogging(this IServiceCollection services) public static IServiceCollection AddFakeLogging(this IServiceCollection services, IConfigurationSection section) public static IServiceCollection AddFakeLogging(this IServiceCollection services, Action<FakeLogCollectorOptions> configure)

After registering the fake logging services, you can resolve the fake logging provider with this method:

public static FakeLogCollector GetFakeLogCollector(this IServiceProvider services)

You can also create an instance of FakeLogger using one of its constructors:

public FakeLogger(FakeLogCollector? collector = null, string? category = null) public FakeLogger(Action<string> outputSink, string? category = null)

You can then use it right away, for example:

var fakeLogger = new FakeLogger<MyComponent>(); // Optionally, you can set the log level // fakeLogger.ControlLevel(LogLevel.Debug, enabled: true); var myComponentUnderTest = new MyComponent(fakeLogger); myComponentUnderTest.DoWork(); // We assume that the component will produce some logs FakeLogCollector collector = fakeLogger.Collector; // Collector allows you to access the captured logs IReadOnlyList<FakeLogRecord> logs = collector.GetSnapshot(); // ... assert that the logs are correct