Project owners can not be no admin

taiga/projects/serializers.py

@@ -190,9 +190,13 @@ def validate_is_admin(self, attrs, source):
         if project is None:
             project = self.object.project
 
-        if (self.object and
-                not services.project_has_valid_admins(project, exclude_user=self.object.user)):
-            raise serializers.ValidationError(_("In this project at least one of the users must be an active admin."))
+        if (self.object):
+            if self.object.user.id == project.owner_id and attrs[source] != True:
+                raise serializers.ValidationError(_("Project owner must be admin."))
+
+            if not services.project_has_valid_admins(project, exclude_user=self.object.user):
+                raise serializers.ValidationError(_("In this project at least one of the users "
+                                                    "must be an active admin."))
 
         return attrs
 

tests/integration/test_memberships.py

@@ -347,6 +347,20 @@ def test_api_edit_membership(client):
 
     assert response.status_code == 200
 
+def test_api_change_owner_membership_to_no_admin_return_error(client):
+    project = f.ProjectFactory()
+    membership_owner = f.MembershipFactory(project=project, user=project.owner, is_admin=True)
+    membership = f.MembershipFactory(project=project, is_admin=True)
+
+    url = reverse("memberships-detail", args=[membership_owner.id])
+    data = {"is_admin": False}
+
+    client.login(membership.user)
+    response = client.json.patch(url, json.dumps(data))
+
+    assert response.status_code == 400
+    assert 'is_admin' in response.data
+
 
 def test_api_delete_membership(client):
     membership = f.MembershipFactory(is_admin=True)