Working on the UserRepository functionality

+ Tests
+ QueryableExtensions. It is an add-on that allows you to implement exceptions if the returned List would be empty.

Govor.Core/Govor.Core.csproj

@@ -10,4 +10,8 @@
       <Folder Include="DTOs\" />
     </ItemGroup>
 
+    <ItemGroup>
+      <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.6" />
+    </ItemGroup>
+
 </Project>

Govor.Core/Infrastructure/Extensions/QueryableExtensions.cs

@@ -0,0 +1,13 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace Govor.Core.Infrastructure.Extensions;
+
+public static class QueryableExtensions
+{
+    public static async Task<List<T>> ToListOrThrowIfEmpty<T>(this IQueryable<T> query, Exception ex)
+    {
+        var list = await query.ToListAsync();
+        if (list.Count == 0) throw ex;
+        return list;
+    }
+}

Govor.Core/Repositories/IUsersReader.cs

@@ -6,9 +6,8 @@ public interface IUsersReader
 {
     public Task<IEnumerable<User>> GetAll();
     public Task<User> FindById(Guid id);
-    public Task<IEnumerable<User>> FindByRangeId(IEnumerable<Guid> ids);
-    public Task<User> FindByUsername(string username);
-    public Task<IEnumerable<User>> FindByRangeUsername(IEnumerable<string> usernames);
-    
-    public Task<IEnumerable<User>> FindUsersByCreatedDate(DateOnly createdDate);
+    public Task<List<User>> FindByRangeId(IEnumerable<Guid> ids);
+    public Task<List<User>> FindUsersByName(string username);
+    public Task<List<User>> FindByRangeUsername(IEnumerable<string> usernames);
+    public Task<List<User>> FindUsersByCreatedDate(DateOnly createdDate);
 }