FEFF.TestFixtures

Integrations:
Fixture libraries:

✅ Replace setup/teardown methods and test-class "Disposable pattern" with reusable Fixtures.
✅ Fixtures can depend on other fixtures.
✅ Fixtures can be configured via standard IServiceProvider.
✅ Set of fixtures to simplify testing AspNetCore applications see full AspNetCore example.

Fixture list

Full Documentation

Prerequisites

.NET 8.0 or later
Test framework: xUnit v3 or TUnit
For ASP.NET Core fixtures: ASP.NET Core 8.0 or later

Getting started (Xunit.V3)

Add a library reference to a test project:

dotnet add package FEFF.TestFixtures.XunitV3

Add an assembly-level attribute to initialize the extension:

[assembly: FEFF.TestFixtures.Xunit.TestFixturesExtension]

Use the TestContext.Current.GetFeffFixture<T>() extension method to get the required fixture instance at any point during a test:

public class SystemUnderTest
{
    public static void Write(string filePath) =>
        File.WriteAllText(filePath, "some-data", Encoding.UTF8);
}

public class ExampleTests
{
    protected TmpDirectoryFixture TmpDir { get; } = TestContext.Current.GetFeffFixture<TmpDirectoryFixture>();

    [Fact]
    public void File__should_be_created()
    {
        // Arrange
        var filePath = TmpDir.Path + "/file.tmp";
        File.Exists(filePath).Should().BeFalse();

        // Act
        SystemUnderTest.Write(filePath);

        // Assert
        File.Exists(filePath)
            .Should().BeTrue();

        File.ReadAllText(filePath, Encoding.UTF8)
            .Should().Be("some-data");
    }
}

In this example, TmpDir is created when the fixture is first requested in the test class constructor. The scope of the fixture in this example is test-case. The TmpDir and its contents are automatically deleted after the test finishes.
This example uses AwesomeAssertions for the Should() assertion DSL.
See the source code for this example.

Defining other scopes for a fixture

The scope of a fixture is defined by the test creator using an overloaded method:

TestContext.Current.GetFeffFixture<T>(FixtureScopeType scopeType)

Also note that multiple instances of the fixture can exist in different scopes if needed.

Creating a fixture

Just create a class with the FixtureAttribute. Let's examine the source code for the TmpDirectoryFixture we used above.

[Fixture]
public sealed class TmpDirectoryFixture : IDisposable
{
    public string Path { get; } = Directory.CreateTempSubdirectory().FullName;

    public void Dispose()
    {
        // double dispose guard
        try
        {
            Directory.Delete(Path, true);
        }
        catch (DirectoryNotFoundException)
        {
        }
    }
}

Fixture Dependencies

Fixtures can depend on other fixtures. Dependencies are injected via the constructor:

[Fixture]
public class MyCustomFixture1
{
}

[Fixture]
public class MyCustomFixture2
{
}

[Fixture]
public record MyFixtureSet(
    MyCustomFixture1 F1,
    MyCustomFixture2 F2,
);

public class ExampleTests
{
    protected MyFixtureSet Set { get; } = TestContext.Current.GetFeffFixture<MyFixtureSet>();

    //...
}

Note:

All fixture dependencies (MyCustomFixture1 and MyCustomFixture2) exist in the same scope as the dependent fixture (MyFixtureSet in the example above).
Fixtures cannot have cyclic dependencies.

Fixture List