check for reactors returning None

fixes #753
bundlewrap · Apr 2, 2024 · 26f21e2 · 26f21e2
1 parent 55dca25
commit 26f21e2
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/bundlewrap/metagen.py b/bundlewrap/metagen.py
@@ -466,6 +466,15 @@ def __run_reactor(self, node, reactor_name, reactor):
         with suppress(KeyError):
             del self._reactors_with_keyerrors[self._current_reactor]
 
+        if new_metadata is None:
+            raise ValueError(_(
+                "{reactor_name} on {node_name} returned None instead of a dict "
+                "(missing return?)"
+            ).format(
+                node_name=node.name,
+                reactor_name=reactor_name,
+            ))
+
         if self._verify_reactor_provides and getattr(reactor, '_provides', None):
             extra_paths = extra_paths_in_dict(new_metadata, reactor._provides)
             if extra_paths: