Add validator tests for brewery and user commands (#282)

web/backend/Features/Features.Users.Tests/Commands/UpdateEmailValidatorTests.cs

@@ -0,0 +1,54 @@
+using Features.Users.Commands.Account.UpdateEmail;
+using FluentValidation.TestHelper;
+
+namespace Features.Users.Tests.Commands;
+
+public class UpdateEmailValidatorTests
+{
+    private readonly UpdateEmailValidator _validator = new();
+
+    private static UpdateEmailCommand ValidCommand() => new(Guid.NewGuid(), "user@example.com");
+
+    [Fact]
+    public void Validate_ValidCommand_HasNoValidationErrors()
+    {
+        TestValidationResult<UpdateEmailCommand> result = _validator.TestValidate(ValidCommand());
+
+        result.ShouldNotHaveAnyValidationErrors();
+    }
+
+    [Fact]
+    public void Validate_EmptyNewEmail_HasErrorForNewEmail()
+    {
+        UpdateEmailCommand command = ValidCommand() with { NewEmail = "" };
+
+        TestValidationResult<UpdateEmailCommand> result = _validator.TestValidate(command);
+
+        result.ShouldHaveValidationErrorFor(x => x.NewEmail).WithErrorMessage("Email is required");
+    }
+
+    [Fact]
+    public void Validate_InvalidEmailFormat_HasErrorForNewEmail()
+    {
+        UpdateEmailCommand command = ValidCommand() with { NewEmail = "not-an-email" };
+
+        TestValidationResult<UpdateEmailCommand> result = _validator.TestValidate(command);
+
+        result
+            .ShouldHaveValidationErrorFor(x => x.NewEmail)
+            .WithErrorMessage("Invalid email format");
+    }
+
+    [Fact]
+    public void Validate_NewEmailTooLong_HasErrorForNewEmail()
+    {
+        string localPart = new('a', 120);
+        UpdateEmailCommand command = ValidCommand() with { NewEmail = $"{localPart}@example.com" };
+
+        TestValidationResult<UpdateEmailCommand> result = _validator.TestValidate(command);
+
+        result
+            .ShouldHaveValidationErrorFor(x => x.NewEmail)
+            .WithErrorMessage("Email cannot exceed 128 characters");
+    }
+}