ThomasW.Domain.SharedKernel.Results.FluentAssertions 0.2.2-alpha.0.1

ThomasW.Domain.SharedKernel.Results.FluentAssertions

FluentAssertions extensions for ThomasW.Domain.SharedKernel.Results.

Installation

This package can be installed via NuGet.

Usage

The package currently provides two assertion methods, BeSuccessful and BeFailed, for both typed and non-typed results.

Simple checks on the success of a result can be made by using the methods with no arguments:

public async Task GetUser_ValidId_ReturnsUser()
{
    // Arrange Act
    Result<User> result = await this._sut.GetUser(this._userId);

    // Assert
    result.Should().BeSuccessful();
}

public async Task GetUser_InvalidId_ReturnsUser()
{
    // Arrange Act
    Result<User> result = await this._sut.GetUser(Guid.NewGuid());

    // Assert
    result.Should().BeFailed();
}

If you want to assert on the value of a successful result, you can pass a predicate into the method. The assertion will only pass if the result is successful and the predicate evaluates to true:

public async Task GetUser_ValidId_ReturnsUser()
{
    // Arrange Act
    Result<User> result = await this._sut.GetUser(this._userId);

    // Assert
    result.Should().BeSuccessful(user => user.Id == this._userId);
}

You can also assert on the failure reason by passing a type argument into the IsFailed method:

public async Task GetUser_InvalidId_ReturnsUser()
{
    // Arrange Act
    Result<User> result = await this._sut.GetUser(Guid.NewGuid());

    // Assert
    result.Should().BeFailed<EntityNotFoundFailure>();
}

This assertion will only pass if the result is failed and the failure reason matches the passed-in type.

Furthermore, you can pass a predicate into the IsFailed method, as well as the type parameter, to assert against the FailureReason object itself:

public async Task GetUser_InvalidId_ReturnsUser()
{
    // Arrange Act
    Result<User> result = await this._sut.GetUser(Guid.NewGuid());

    // Assert
    result.Should().BeFailed<EntityNotFoundFailure>(
        reason => reason.Message == "User not found");
}

The above assertion will only pass if the result is failed, the failure reason matches the passed-in type and the predicate evaluates to true.