Improve friends search and error handling in API

Refactored FriendsController to provide more precise error responses and input validation. Enhanced FriendsService to handle new exception types and improved user search logic. Added tests for user search, updated repository to throw on empty search results, and implemented User equality override. Cleaned up Program.cs controller JSON options.

Govor.Application/Interfaces/IFriendsService.cs

@@ -4,7 +4,7 @@ namespace Govor.Application.Interfaces;
 
 public interface IFriendsService
 {
-    Task<List<User>> SearchUsersAsync(string searchTerm, Guid currentId);
+    Task<List<User>> SearchUsersAsync(string query, Guid currentId);
     Task SendFriendRequestAsync(Guid fromUserId, Guid toUserId);
     Task AcceptFriendRequestAsync(Guid requestId, Guid currentUserId);
     Task<List<User>> GetFriendsAsync(Guid userId);

Govor.Application/Services/FriendsService.cs

@@ -19,12 +19,14 @@ public class FriendsService : IFriendsService
         _friendshipsRepository = relationshipsRepository;
     }
     
-    public async Task<List<User>> SearchUsersAsync(string searchTerm, Guid currentId)
+    public async Task<List<User>> SearchUsersAsync(string query, Guid currentId)
     {
-        var all = await _usersRepository.SearchPotentialFriendsAsync(currentId, searchTerm);
-
+        List<User> all = new List<User>();
+        
         try
         {
+            all = await _usersRepository.SearchPotentialFriendsAsync(currentId, query);
+
             var friends = await _friendshipsRepository.FindByUserIdAsync(currentId);
 
             friends = friends.Where(f => f.Status == FriendshipStatus.Accepted).ToList();
@@ -33,13 +35,18 @@ public class FriendsService : IFriendsService
                 .Where(u => u.Id != currentId && !friends.Select(f => f.RequesterId).Contains(u.Id))
                 .ToList();
         }
+        catch (NotFoundByKeyException<(string, Guid)> ex)
+        {
+            throw new SearchUsersException(
+                $"Users with given query: \"{query}\" for user with id {currentId} was not found", ex);
+        }
         catch (NotFoundByKeyException<Guid> ex)
         {
             return all.Where(u => u.Id != currentId).ToList();
         }
         catch (Exception ex)
         {
-            throw new SearchUsersException($"When we try find friends by pattern {searchTerm} something wrong", ex);
+            throw new UnauthorizedAccessException($"When we try find friends by pattern {query} something wrong", ex);
         }
     }
 
@@ -85,21 +92,16 @@ public class FriendsService : IFriendsService
     {
         try
         {
-            var user = await _usersRepository.FindByIdAsync(userId);
+            var friendships = await _friendshipsRepository.FindByUserIdAsync(userId);
 
-            var sent = user.SentFriendRequests
+            return friendships
                 .Where(f => f.Status == FriendshipStatus.Accepted)
-                .Select(f => f.Addressee);
-
-            var received = user.ReceivedFriendRequests
-                .Where(f => f.Status == FriendshipStatus.Accepted)
-                .Select(f => f.Requester);
-
-            return sent.Concat(received).ToList();
+                .Select(f => f.RequesterId == userId ? f.Addressee : f.Requester)
+                .ToList();
         }
         catch (NotFoundByKeyException<Guid> ex)
         {
-            throw new InvalidOperationException("User not exist", ex);
+            throw new InvalidOperationException("User not found", ex);
         }
     }