Add friendship feature with models, repository, and tests

Introduces Friendship and PrivateChat models, repository interfaces, and implementations for managing friendships. Adds validators and comprehensive unit and integration tests for friendship logic. Updates InviteUserController with new endpoints and restricts access to admin role. Removes unnecessary project references from Govor.API.csproj and registers new DbSets in GovorDbContext.

Govor.API.Tests/UnitTests/Infrastructure/Validators/FriendshipValidatorTests.cs

@@ -0,0 +1,70 @@
+using AutoFixture;
+using Govor.Core.Infrastructure.Validators;
+using Govor.Core.Models;
+
+namespace Govor.API.Tests.UnitTests.Infrastructure.Validators;
+
+[TestFixture]
+public class FriendshipValidatorTests
+{
+    private IObjectValidator<Friendship> _friendshipValidator;
+    private Fixture _fixture;
+    
+    public FriendshipValidatorTests()
+    {
+        _friendshipValidator = new FriendshipValidator();
+        
+        _fixture = new Fixture();
+
+        _fixture.Behaviors
+            .OfType<ThrowingRecursionBehavior>()
+            .ToList()
+            .ForEach(b => _fixture.Behaviors.Remove(b));
+
+        _fixture.Behaviors.Add(new OmitOnRecursionBehavior());
+    }
+    
+        
+    [Test]
+    public void Given_ValidFriendship_When_Validate_Then_Returns_True()
+    {
+        var friendship = _fixture.Create<Friendship>();
+        
+        // Act & Assert 
+        Assert.DoesNotThrow( () => _friendshipValidator.Validate(friendship));
+        Assert.That(_friendshipValidator.TryValidate(friendship), Is.True);
+    }
+    
+    [Test]
+    public void Given_EmptyFriendshipId_When_Validate_Then_Returns_False()
+    {
+        var friendship = _fixture.Create<Friendship>();
+        friendship.Id = Guid.Empty;
+        
+        // Act & Assert 
+        Assert.Throws<InvalidObjectException<Friendship>>( () => _friendshipValidator.Validate(friendship));
+        Assert.That(_friendshipValidator.TryValidate(friendship), Is.False);
+    }
+    
+    [Test]
+    public void Given_EmptyRequesterId_When_Validate_Then_Returns_False()
+    {
+        var friendship = _fixture.Create<Friendship>();
+        friendship.RequesterId = Guid.Empty;
+        
+        // Act & Assert 
+        Assert.Throws<InvalidObjectException<Friendship>>( () => _friendshipValidator.Validate(friendship));
+        Assert.That(_friendshipValidator.TryValidate(friendship), Is.False);
+    }
+    
+    [Test]
+    public void Given_AddresseeId_When_Validate_Then_Returns_False()
+    {
+        var friendship = _fixture.Create<Friendship>();
+        friendship.AddresseeId = Guid.Empty;
+        
+        // Act & Assert 
+        Assert.Throws<InvalidObjectException<Friendship>>( () => _friendshipValidator.Validate(friendship));
+        Assert.That(_friendshipValidator.TryValidate(friendship), Is.False);
+    }
+}

Govor.API.Tests/UnitTests/Infrastructure/Validators/InvitationValidatorTests.cs

@@ -25,7 +25,7 @@ public class InvitationValidatorTests
     }
     
     [Test]
-    public void Given_ValidInvitation_When_Exist_Then_Returns_True()
+    public void Given_ValidInvitation_When_Validate_Then_Returns_True()
     {
         var invitation = _fixture.Create<Invitation>();
         
@@ -35,7 +35,7 @@ public class InvitationValidatorTests
     }
 
     [Test]
-    public void Given_NullInvitation_When_Exist_Then_Returns_False()
+    public void Given_NullInvitation_When_Validate_Then_Returns_False()
     {
         // Act & Assert 
         Assert.Throws<InvalidObjectException<Invitation>>( () => _messageValidator.Validate(default));
@@ -43,7 +43,7 @@ public class InvitationValidatorTests
     }
     
     [Test]
-    public void Given_EmptyInvitationId_When_Exist_Then_Returns_False()
+    public void Given_EmptyInvitationId_When_Validate_Then_Returns_False()
     {
         // Arrange 
         var invitation = _fixture.Create<Invitation>();
@@ -55,7 +55,7 @@ public class InvitationValidatorTests
     }
     
     [Test]
-    public void Given_EmptyInvitationCreationDate_When_Exist_Then_Returns_False()
+    public void Given_EmptyInvitationCreationDate_When_Validate_Then_Returns_False()
     {
         // Arrange 
         var invitation = _fixture.Create<Invitation>();
@@ -67,7 +67,7 @@ public class InvitationValidatorTests
     }
     
     [Test]
-    public void Given_InvalidEndDatesAndIsActive_When_Exist_Then_Returns_False()
+    public void Given_InvalidEndDatesAndIsActive_When_Validate_Then_Returns_False()
     {
         // Arrange 
         var invitation = _fixture.Create<Invitation>();
@@ -79,7 +79,7 @@ public class InvitationValidatorTests
     }
     
     [Test]
-    public void Given_InvalidMaxParticipantsAndIsActive_When_Exist_Then_Returns_False()
+    public void Given_InvalidMaxParticipantsAndIsActive_When_Validate_Then_Returns_False()
     {
         // Arrange 
         var invitation = _fixture.Create<Invitation>();
@@ -92,7 +92,7 @@ public class InvitationValidatorTests
     }
     
     [Test]
-    public void Given_InvalidCode_When_Exist_Then_Returns_False()
+    public void Given_InvalidCode_When_Validate_Then_Returns_False()
     {
         // Arrange 
         var invitation = _fixture.Create<Invitation>();