Add unit tests

tests/WebApi.Tests.Unit/Cars/UpdateCarRequestValidatorTests.cs

@@ -0,0 +1,71 @@
+using FluentAssertions;
+using Vegasco.WebApi.Cars;
+
+namespace WebApi.Tests.Unit.Cars;
+
+public sealed class UpdateCarRequestValidatorTests
+{
+	private readonly UpdateCar.Validator _sut = new();
+
+	private readonly UpdateCar.Request _validRequest = new("Ford Focus");
+
+	[Fact]
+	public async Task ValidateAsync_ShouldBeValid_WhenRequestIsValid()
+	{
+		// Arrange
+
+		// Act
+		var result = await _sut.ValidateAsync(_validRequest);
+
+		// Assert
+		result.IsValid.Should().BeTrue();
+	}
+
+	[Theory]
+	[InlineData(1)]
+	[InlineData(50)]
+	public async Task ValidateAsync_ShouldBeValid_WhenNameIsJustWithinTheLimits(int nameLength)
+	{
+		// Arrange
+		var request = _validRequest with { Name = new string('s', nameLength) };
+
+		// Act
+		var result = await _sut.ValidateAsync(request);
+
+		// Assert
+		result.IsValid.Should().BeTrue();
+	}
+
+	[Fact]
+	public async Task ValidateAsync_ShouldNotBeValid_WhenNameIsEmpty()
+	{
+		// Arrange
+		var request = _validRequest with { Name = "" };
+
+		// Act
+		var result = await _sut.ValidateAsync(request);
+
+		// Assert
+		result.IsValid.Should().BeFalse();
+		result.Errors.Should().ContainSingle()
+			.Which
+			.PropertyName.Should().Be(nameof(UpdateCar.Request.Name));
+	}
+
+	[Fact]
+	public async Task ValidateAsync_ShouldNotBeValid_WhenNameIsTooLong()
+	{
+		// Arrange
+		const int nameMaxLength = 50;
+		var request = _validRequest with { Name = new string('s', nameMaxLength + 1) };
+
+		// Act
+		var result = await _sut.ValidateAsync(request);
+
+		// Assert
+		result.IsValid.Should().BeFalse();
+		result.Errors.Should().ContainSingle()
+			.Which
+			.PropertyName.Should().Be(nameof(UpdateCar.Request.Name));
+	}
+}