Add self-service account management commands (delete, update username/email/password/profile)

web/backend/Features/Features.Auth.Tests/Commands/UpdateUsernameHandlerTests.cs

@@ -0,0 +1,84 @@
+using Domain.Exceptions;
+using Features.Auth.Commands.UpdateUsername;
+using Features.Auth.Dtos;
+using Features.Auth.Identity;
+using Features.Auth.Tests.TestSupport;
+using FluentAssertions;
+using Microsoft.AspNetCore.Identity;
+using Moq;
+
+namespace Features.Auth.Tests.Commands;
+
+public class UpdateUsernameHandlerTests
+{
+    private readonly UpdateUsernameHandler _handler;
+    private readonly Mock<UserManager<ApplicationUser>> _userManagerMock;
+
+    public UpdateUsernameHandlerTests()
+    {
+        _userManagerMock = UserManagerMockFactory.Create();
+        _handler = new UpdateUsernameHandler(_userManagerMock.Object);
+    }
+
+    [Fact]
+    public async Task Handle_WithValidRequest_UpdatesUsername()
+    {
+        Guid userId = Guid.NewGuid();
+        ApplicationUser user = new() { Id = userId, UserName = "old-name" };
+
+        _userManagerMock.Setup(x => x.FindByIdAsync(userId.ToString())).ReturnsAsync(user);
+        _userManagerMock
+            .Setup(x => x.SetUserNameAsync(user, "new-name"))
+            .Callback<ApplicationUser, string>((u, n) => u.UserName = n)
+            .ReturnsAsync(IdentityResult.Success);
+
+        UpdateUsernamePayload result = await _handler.Handle(
+            new UpdateUsernameCommand(userId, "new-name"),
+            CancellationToken.None
+        );
+
+        result.UserAccountId.Should().Be(userId);
+        result.Username.Should().Be("new-name");
+    }
+
+    [Fact]
+    public async Task Handle_WithNonExistentUser_ThrowsNotFoundException()
+    {
+        Guid userId = Guid.NewGuid();
+        _userManagerMock
+            .Setup(x => x.FindByIdAsync(userId.ToString()))
+            .ReturnsAsync((ApplicationUser?)null);
+
+        Func<Task<UpdateUsernamePayload>> act = async () =>
+            await _handler.Handle(
+                new UpdateUsernameCommand(userId, "new-name"),
+                CancellationToken.None
+            );
+
+        await act.Should().ThrowAsync<NotFoundException>();
+    }
+
+    [Fact]
+    public async Task Handle_WithDuplicateUsername_ThrowsConflictException()
+    {
+        Guid userId = Guid.NewGuid();
+        ApplicationUser user = new() { Id = userId, UserName = "old-name" };
+
+        _userManagerMock.Setup(x => x.FindByIdAsync(userId.ToString())).ReturnsAsync(user);
+        _userManagerMock
+            .Setup(x => x.SetUserNameAsync(user, "taken-name"))
+            .ReturnsAsync(
+                IdentityResult.Failed(
+                    new IdentityError { Code = "DuplicateUserName", Description = "taken" }
+                )
+            );
+
+        Func<Task<UpdateUsernamePayload>> act = async () =>
+            await _handler.Handle(
+                new UpdateUsernameCommand(userId, "taken-name"),
+                CancellationToken.None
+            );
+
+        await act.Should().ThrowAsync<ConflictException>();
+    }
+}