refactor: disallow registering user when phone is already used

Server/ReasnAPI/ReasnAPI.Tests/UnitTests/Services/Authentication/AuthServiceTests.cs

@@ -28,7 +28,8 @@ public void Setup()
         {
             Email = "[email protected]",
             Username = "jsnow",
-            Password = _hasher.HashPassword(null!, "password")
+            Password = _hasher.HashPassword(null!, "password"),
+            Phone = "+123 456789"
         };
 
         _mockContext.Setup(c => c.Users)
@@ -96,6 +97,19 @@ public void Register_WhenUserWithUsernameAlreadyExists_ShouldThrowBadRequestExce
         Assert.ThrowsException<BadRequestException>(() => _service.Register(request));
     }
 
+    [TestMethod]
+    public void Register_WhenUserWithPhoneAlreadyExists_ShouldThrowBadRequestException()
+    {
+        var request = new RegisterRequest
+        {
+            Email = "[email protected]",
+            Username = "jstark",
+            Phone = "+123 456789"
+        };
+
+        Assert.ThrowsException<BadRequestException>(() => _service.Register(request));
+    }
+
     [TestMethod]
     public void Register_WhenUserDoesNotExist_ShouldReturnRegisteredUser()
     {
@@ -106,7 +120,7 @@ public void Register_WhenUserDoesNotExist_ShouldReturnRegisteredUser()
             Email = "[email protected]",
             Username = "jstark",
             Password = "S3cureP@ssword!",
-            Phone = "+123 456789",
+            Phone = "+123 456781",
             Address = new AddressDto
             {
                 Street = "The Wall",

Server/ReasnAPI/ReasnAPI/Services/Authentication/AuthService.cs

@@ -43,12 +43,13 @@ public User Register(RegisterRequest request)
     {
         var userAlreadyExists = _context.Users.Any(u =>
             u.Email.ToUpper() == request.Email.ToUpper() ||
-            u.Username.ToUpper() == request.Username.ToUpper());
+            u.Username.ToUpper() == request.Username.ToUpper() ||
+            u.Phone == request.Phone);
 
         if (userAlreadyExists)
         {
             throw new BadRequestException(
-                "User with provided email or username already exists");
+                "User with provided email, username or phone already exists");
         }
 
         var user = new User