Created tests for the core module

tests/HopFrame.Core.Tests/Models/MockDbContext.cs

@@ -0,0 +1,13 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace HopFrame.Core.Tests.Models;
+
+// A mock DbContext for testing purposes
+public class MockDbContext : DbContext {
+    public DbSet<MockModel> Models { get; set; }
+    public DbSet<MockModel2> Models2 { get; set; }
+
+    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
+        optionsBuilder.UseInMemoryDatabase(nameof(MockDbContext));
+    }
+}