Implement get user by id

Core/Dtos/Users/UserPreviewDto.cs

@@ -0,0 +1,3 @@
+namespace EUniversity.Core.Dtos.Users;
+
+public record UserPreviewDto(string Id, string Email, string UserName, string FirstName, string LastName, string? MiddleName);

Core/Dtos/Users/UserViewDto.cs

@@ -1,3 +1,13 @@
 namespace EUniversity.Core.Dtos.Users;
 
-public record UserViewDto(string Id, string Email, string UserName, string FirstName, string LastName, string? MiddleName);
+public class UserViewDto
+{
+    public string Id { get; set; } = null!;
+    public string Email { get; set; } = null!;
+    public string UserName { get; set; } = null!;
+    public string FirstName { get; set; } = null!;
+    public string LastName { get; set; } = null!;
+    public string? MiddleName { get; set; }
+    public bool IsDeleted { get; set; }
+    public IEnumerable<string> Roles { get; set; } = null!;
+}

Core/Services/Users/IUsersService.cs

@@ -19,7 +19,7 @@ public interface IUsersService
     /// <returns>
     /// Page with all users with the role.
     /// </returns>
-    Task<Page<UserViewDto>> GetUsersInRoleAsync(string role, PaginationProperties? properties = null,
+    Task<Page<UserPreviewDto>> GetUsersInRoleAsync(string role, PaginationProperties? properties = null,
         IFilter<ApplicationUser>? filter = null);
 
     /// <summary>
@@ -33,9 +33,19 @@ Task<Page<UserViewDto>> GetUsersInRoleAsync(string role, PaginationProperties? p
     /// <returns>
     /// Page with all users.
     /// </returns>
-    Task<Page<UserViewDto>> GetAllUsersAsync(PaginationProperties? properties = null, 
+    Task<Page<UserPreviewDto>> GetAllUsersAsync(PaginationProperties? properties = null, 
         IFilter<ApplicationUser>? filter = null, bool onlyDeleted = false);
 
+    /// <summary>
+    /// Gets a user by its ID.
+    /// </summary>
+    /// <param name="id"></param>
+    /// <returns>
+    /// A task that represents the asynchronous operation.
+    /// Returns <see langword="null" /> if user is not found.
+    /// </returns>
+    Task<UserViewDto?> GetByIdAsync(string id);
+
     /// <summary>
     /// Deletes a user identified by its unique identifier asynchronously.
     /// </summary>

EUniversity/Controllers/UsersController.cs

@@ -45,7 +45,7 @@ public UsersController(IAuthService authService, IUsersService usersService)
     /// <response code="401">Unauthorized user call</response>
     /// <response code="403">User lacks 'Administrator' role</response>
     [HttpGet]
-    [ProducesResponseType(typeof(Page<UserViewDto>), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(Page<UserPreviewDto>), StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status401Unauthorized)]
     [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<IActionResult> GetAllUsersAsync(
@@ -76,7 +76,7 @@ public async Task<IActionResult> GetAllUsersAsync(
     /// <response code="403">User lacks 'Administrator' role</response>
     [HttpGet]
     [Route("students")]
-    [ProducesResponseType(typeof(Page<UserViewDto>), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(Page<UserPreviewDto>), StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status401Unauthorized)]
     [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<IActionResult> GetAllStudentsAsync(
@@ -107,7 +107,7 @@ public async Task<IActionResult> GetAllStudentsAsync(
     /// <response code="403">User lacks 'Administrator' role</response>
     [HttpGet]
     [Route("teachers")]
-    [ProducesResponseType(typeof(Page<UserViewDto>), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(Page<UserPreviewDto>), StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status401Unauthorized)]
     [ProducesResponseType(StatusCodes.Status403Forbidden)]
     public async Task<IActionResult> GetAllTeachersAsync(

Infrastructure/Services/Users/UsersService.cs

@@ -18,7 +18,7 @@ public UsersService(ApplicationDbContext dbContext)
         _dbContext = dbContext;
     }
 
-    private static async Task<Page<UserViewDto>> SelectUsersAsync(
+    private static async Task<Page<UserPreviewDto>> SelectUsersAsync(
         IQueryable<ApplicationUser> query,
         PaginationProperties? properties,
         IFilter<ApplicationUser>? filter,
@@ -27,18 +27,18 @@ private static async Task<Page<UserViewDto>> SelectUsersAsync(
         query = query.AsNoTracking()
             .Where(u => u.IsDeleted == onlyDeleted);
         query = filter?.Apply(query) ?? query;
-        return await query.ToPageAsync<ApplicationUser, UserViewDto>(properties);
+        return await query.ToPageAsync<ApplicationUser, UserPreviewDto>(properties);
     }
 
     /// <inheritdoc />
-    public async Task<Page<UserViewDto>> GetAllUsersAsync(PaginationProperties? properties,
+    public async Task<Page<UserPreviewDto>> GetAllUsersAsync(PaginationProperties? properties,
         IFilter<ApplicationUser>? filter = null, bool onlyDeleted = false)
     {
         return await SelectUsersAsync(_dbContext.Users, properties, filter, onlyDeleted);
     }
 
     /// <inheritdoc />
-    public async Task<Page<UserViewDto>> GetUsersInRoleAsync(string role, PaginationProperties? properties,
+    public async Task<Page<UserPreviewDto>> GetUsersInRoleAsync(string role, PaginationProperties? properties,
         IFilter<ApplicationUser>? filter = null)
     {
         string? roleId = await _dbContext.Roles
@@ -48,11 +48,32 @@ public async Task<Page<UserViewDto>> GetUsersInRoleAsync(string role, Pagination
             throw new InvalidOperationException($"Role {role} doesn't exists");
 
         var users = _dbContext.UserRoles
-            .Where(r => r.RoleId == roleId)
-            .Join(_dbContext.Users, r => r.UserId, u => u.Id, (r, u) => u);
+            .AsNoTracking()
+            .Where(ur => ur.RoleId == roleId)
+            .Join(_dbContext.Users, r => r.UserId, u => u.Id, (ur, u) => u);
         return await SelectUsersAsync(users, properties, filter, false);
     }
 
+    /// <inheritdoc />
+    public async Task<UserViewDto?> GetByIdAsync(string id)
+    {
+        var user = await _dbContext.Users
+            .AsNoTracking()
+            .Where(u => u.Id == id)
+            .FirstOrDefaultAsync();
+        if (user == null) return null;
+
+        var dto = user.Adapt<UserViewDto>();
+        // Select user's roles
+        dto.Roles = await _dbContext.UserRoles
+            .AsNoTracking()
+            .Where(ur => ur.UserId == id)
+            .Join(_dbContext.Roles, ur => ur.RoleId, r => r.Id, (ur, r) => r)
+            .Select(r => r.Name!)
+            .ToListAsync();
+        return dto;
+    }
+
     /// <inheritdoc />
     public async Task<bool> DeleteUserAsync(string userId)
     {

IntegrationTests/Controllers/UsersControllerTests.cs

@@ -25,7 +25,7 @@ public class UsersControllerTests : ControllersTest
             RegisterUser2
         });
 
-    public UserViewDto[] TestUsers =
+    public UserPreviewDto[] TestUsers =
     {
         new("1", "mail1@example.com", "user1", "First1", "Last1", null),
         new("2", "mail2@example.com", "user2", "First2", "Last2", "Middle2")
@@ -56,7 +56,7 @@ public static readonly (string, string)[] RegisterMethodsWithRoles =
         (RolesGetMethods[1], Roles.Teacher)
     };
 
-    private Page<UserViewDto> GetTestPage(PaginationProperties paginationProperties)
+    private Page<UserPreviewDto> GetTestPage(PaginationProperties paginationProperties)
     {
         return new(TestUsers, paginationProperties, TestUsers.Length);
     }
@@ -84,7 +84,7 @@ public async Task GetMethods_AdministratorRole_SucceedAndReturnValidType(string
 
         // Assert
         result.EnsureSuccessStatusCode();
-        var users = await result.Content.ReadFromJsonAsync<Page<UserViewDto>>();
+        var users = await result.Content.ReadFromJsonAsync<Page<UserPreviewDto>>();
         Assert.That(users, Is.Not.Null);
     }
 
@@ -101,7 +101,7 @@ public async Task GetMethods_PaginationQueryParams_SucceedAndApplyPagination(str
 
         // Assert
         result.EnsureSuccessStatusCode();
-        var usersPage = await result.Content.ReadFromJsonAsync<Page<UserViewDto>>();
+        var usersPage = await result.Content.ReadFromJsonAsync<Page<UserPreviewDto>>();
         Assert.That(usersPage, Is.Not.Null);
         Assert.Multiple(() =>
         {
@@ -122,7 +122,7 @@ public async Task GetAllUsers_FilterQueryParams_SucceedsAndAppliesFilter()
 
         // Assert
         result.EnsureSuccessStatusCode();
-        var usersPage = await result.Content.ReadFromJsonAsync<Page<UserViewDto>>();
+        var usersPage = await result.Content.ReadFromJsonAsync<Page<UserPreviewDto>>();
         Assert.That(usersPage, Is.Not.Null);
         await WebApplicationFactory.UsersServiceMock
             .Received()
@@ -142,7 +142,7 @@ public async Task GetUsersInRoleMethods_FilterQueryParams_SucceedAndApplyFilter(
 
         // Assert
         result.EnsureSuccessStatusCode();
-        var usersPage = await result.Content.ReadFromJsonAsync<Page<UserViewDto>>();
+        var usersPage = await result.Content.ReadFromJsonAsync<Page<UserPreviewDto>>();
         Assert.That(usersPage, Is.Not.Null);
         await WebApplicationFactory.UsersServiceMock
             .Received()

IntegrationTests/Services/UsersServiceTests.cs

@@ -1,4 +1,5 @@
-using EUniversity.Core.Filters;
+using EUniversity.Core.Dtos.Users;
+using EUniversity.Core.Filters;
 using EUniversity.Core.Models;
 using EUniversity.Core.Pagination;
 using EUniversity.Core.Policy;
@@ -180,7 +181,7 @@ public async Task GetUsersInRole_ReturnsUsersInRole()
     }
 
     [Test]
-    public virtual async Task DeleteUser_UserExists_Succeeds()
+    public async Task DeleteUser_UserExists_Succeeds()
     {
         // Arrange
         ApplicationUser user = new()
@@ -205,7 +206,7 @@ public virtual async Task DeleteUser_UserExists_Succeeds()
     }
 
     [Test]
-    public virtual async Task DeleteUser_UserDoesNotExist_ReturnsFalse()
+    public async Task DeleteUser_UserDoesNotExist_ReturnsFalse()
     {
         // Arrange
         string fakeId = "null";
@@ -218,7 +219,7 @@ public virtual async Task DeleteUser_UserDoesNotExist_ReturnsFalse()
     }
 
     [Test]
-    public virtual async Task DeleteUser_UserIsDeleted_ReturnsFalse()
+    public async Task DeleteUser_UserIsDeleted_ReturnsFalse()
     {
         // Arrange
         ApplicationUser user = new()
@@ -237,4 +238,38 @@ public virtual async Task DeleteUser_UserIsDeleted_ReturnsFalse()
         // Assert
         Assert.That(result, Is.False);
     }
+
+    [Test]
+    public async Task GetUserById_UserExists_ReturnsUserWithRoles()
+    {
+        // Arrange
+        string[] roles = { Roles.Administrator, Roles.Teacher };
+        var user = await RegisterTestUserAsync(roles);
+
+        // Act
+        var result = await _usersService.GetByIdAsync(user.Id);
+
+        // Assert
+        Assert.That(result, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(result.Id, Is.EqualTo(user.Id));
+            Assert.That(result.FirstName, Is.EqualTo(user.FirstName));
+            Assert.That(result.Email, Is.EqualTo(user.Email));
+            Assert.That(result.Roles, Is.EquivalentTo(roles));
+        });
+    }
+
+    [Test]
+    public async Task GetUserById_UserDoesNotExist_ReturnsNull()
+    {
+        // Arrange
+        string fakeId = "null";
+
+        // Act
+        var result = await _usersService.GetByIdAsync(fakeId);
+
+        // Assert
+        Assert.That(result, Is.Null);
+    }
 }