SystemExtensions/SystemExtensions.Tests/Extensions/ResultTests.cs

using FluentAssertions;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace System.Extensions.Tests;

[TestClass]
public class ResultTests
{
    [TestMethod]
    public void SuccessResultShouldCreateFromSuccess()
    {
        var success = string.Empty;
        var result = Result<string, object>.Success(success);

        result.DoAny(
            onFailure: () => throw new InvalidOperationException());
    }

    [TestMethod]
    public void FailureResultShouldCreateFromFailure()
    {
        var failure = new object();
        var result = Result<string, object>.Failure(failure);

        result.DoAny(
            onSuccess: () => throw new InvalidOperationException());
    }

    [TestMethod]
    public void DoShouldExecute()
    {
        var success = string.Empty;
        var successResult = Result<string, object>.Success(success);

        var failure = new object();
        var failedResult = Result<string, object>.Failure(failure);

        successResult.Do(
            onSuccess: _ => { },
            onFailure: _ => throw new InvalidOperationException());

        failedResult.Do(
            onSuccess: _ => throw new InvalidOperationException(),
            onFailure: _ => { });
    }

    [TestMethod]
    public void DoAnyShouldExecute()
    {
        var success = string.Empty;
        var successResult = Result<string, object>.Success(success);

        var failure = new object();
        var failedResult = Result<string, object>.Failure(failure);

        successResult.DoAny(
            onSuccess: _ => { });

        failedResult.DoAny(
            onFailure: _ => { });
    }

    [TestMethod]
    public void SwitchShouldExecute()
    {
        var success = string.Empty;
        var successResult = Result<string, object>.Success(success);

        var failure = new object();
        var failedResult = Result<string, object>.Failure(failure);

        var successSwitch = successResult.Switch(
            onSuccess: _ => string.Empty,
            onFailure: _ => throw new InvalidOperationException());

        var failedSwitch = failedResult.Switch(
            onSuccess: _ => throw new InvalidOperationException(),
            onFailure: _ => string.Empty);

        success.Should().Be(failedSwitch);
    }

    [TestMethod]
    public void SwitchAnyShouldExecute()
    {
        var success = string.Empty;
        var successResult = Result<string, object>.Success(success);

        var failure = new object();
        var failedResult = Result<string, object>.Failure(failure);

        var successSwitch = successResult.SwitchAny(
            onSuccess: _ => string.Empty);

        var failedSwitch = failedResult.SwitchAny(
            onFailure: _ => string.Empty);

        success.Should().Be(failedSwitch);
    }

    [TestMethod]
    public void ToOptionalShouldConvert()
    {
        var success = string.Empty;
        var successResult = Result<string, object>.Success(success);

        var failure = new object();
        var failedResult = Result<string, object>.Failure(failure);

        var successOptional = successResult.ToOptional();
        var failureOptional = failedResult.ToOptional();

        successOptional.Should().NotBeNull();
        failureOptional.Should().NotBeNull();
    }
}