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Version: v2.0

Functional.xunit

UnambitiousFx.Functional.xunit adds fluent assertions for Result and Maybe<T> in xUnit tests.

Introduction​

Use this package to make tests expressive and intention-revealing:

  • Assert success and failure without verbose boilerplate.
  • Inspect typed failures with fluent chaining.
  • Keep async and sync assertions consistent.

Install​

dotnet add package UnambitiousFx.Functional.xunit

Core Concepts​

Every assertion starts from ShouldBe() and then narrows the expected case:

  • result.ShouldBe().Success() for success branches
  • result.ShouldBe().Failure() for failure branches
  • maybe.ShouldBe().Some() and maybe.ShouldBe().None() for optional values

This style keeps tests readable while still enabling deep checks through Where, WhichIs<TFailure>(), and And(...).

Simple Example​

using UnambitiousFx.Functional.Failures;
using UnambitiousFx.Functional.xunit;

[Fact]
public void Parse_InvalidValue_ReturnsValidationFailure()
{
    var result = Parse("abc");

    result.ShouldBe()
        .Failure()
        .WhichIs<ValidationFailure>()
        .And(failure => Assert.Contains("integer", failure.Message));
}

Advanced Concepts​

Async Support​

The package includes assertion extensions for ValueTask<Result<T>> and ValueTask<Maybe<T>>.

Use the same ShouldBe() pattern after awaiting values in your tests.

See Also​