Add invitation code validation and auto-generation for guests

Validate uniqueness of invitation codes during guest creation to prevent duplicates. Automatically generate an 8-character code if none is provided, ensuring consistent data handling. Updated tests and schemas to support these changes.

backend/tests/api/routes/events/test_guests.py

@@ -39,6 +39,33 @@ class TestGuestsRouter:
         assert data["full_name"] == guest_data["full_name"]
         assert data["email"] == guest_data["email"]
 
+    def test_create_guest_fails_on_duplicate_invitation_code(self, guest_data):
+        # First create the guest successfully
+        response_initial = self.client.post(self.endpoint, json=guest_data)
+        assert response_initial.status_code == 200
+
+        # Attempt to create another guest with the same invitation code
+        new_guest_data = guest_data.copy()
+        new_guest_data["email"] = "new.email@example.com"
+        response_duplicate = self.client.post(self.endpoint, json=new_guest_data)
+
+        assert response_duplicate.status_code == 400
+        assert response_duplicate.json()["detail"] == "Guest with this invitation code already exists"
+
+
+    def test_create_guest_generates_invitation_code_if_not_provided(self, guest_data):
+        # Remove invitation_code to test auto-generation
+        guest_data_without_code = guest_data.copy()
+        guest_data_without_code.pop("invitation_code", None)
+
+        response = self.client.post(self.endpoint, json=guest_data_without_code)
+        assert response.status_code == 200
+
+        data = response.json()
+        print(data)
+        assert "invitation_code" in data
+        assert len(data["invitation_code"]) == 8
+
     def test_create_guest_missing_required_fields_fails(self):
         incomplete_payload = {
             "email": "john.doe@example.com"