Don't allow creating/updating interest with empty name

backend/models/dtos/interests_dto.py

@@ -7,7 +7,7 @@ class InterestDTO(Model):
     """DTO for a interest."""
 
     id = IntType()
-    name = StringType()
+    name = StringType(required=True, min_length=1)
     user_selected = BooleanType(
         serialized_name="userSelected", serialize_when_none=False
     )

tests/backend/integration/api/interests/test_resources.py

@@ -95,6 +95,21 @@ def test_create_a_new_interest_by_organisation_admin_passes(self):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response_body["name"], NEW_INTEREST_NAME)
 
+    def test_create_a_new_interest_with_empty_name_fails(self):
+        """
+        Test that endpoint returns 400 when admin creates a new interest with empty name
+        """
+        # setup: make test user organisation admin
+        add_manager_to_organisation(self.test_organisation, self.test_user)
+        response = self.client.post(
+            self.endpoint_url,
+            headers={"Authorization": self.session_token},
+            json={"name": ""},
+        )
+        response_body = response.get_json()
+        self.assertEqual(response.status_code, 400)
+        self.assertEqual(response_body["SubCode"], "InvalidData")
+
     # get
     def test_get_all_interest_passes(self):
         """
@@ -230,6 +245,21 @@ def test_update_an_existent_interest_with_invalid_data_fails(self):
         self.assertEqual(response.status_code, 400)
         self.assertEqual(response_body["SubCode"], "InvalidData")
 
+    def test_update_an_interest_with_empty_name_fails(self):
+        """
+        Test that endpoint returns 400 when updating an interest with empty name
+        """
+        # setup: make test user organisation admin
+        add_manager_to_organisation(self.test_organisation, self.test_user)
+        response = self.client.patch(
+            self.endpoint_url,
+            headers={"Authorization": self.session_token},
+            json={"name": ""},
+        )
+        response_body = response.get_json()
+        self.assertEqual(response.status_code, 400)
+        self.assertEqual(response_body["SubCode"], "InvalidData")
+
     def test_update_an_existing_interest_by_organisation_admin_passes(self):
         """
         Test that endpoint returns 200 when updating an existing interest by admin