even more safety

Author: ianhi

src/zarr/testing/stateful.py

@@ -340,11 +340,12 @@ def delete_array_using_del(self, data: DataObject) -> None:
         self.all_arrays.remove(array_path)
 
     @precondition(lambda self: self.store.supports_deletes)
-    @precondition(lambda self: bool(self.all_groups))
+    @precondition(lambda self: bool(self.all_groups - {"", "/"}))
     @rule(data=st.data())
     def delete_group_using_del(self, data: DataObject) -> None:
         group_path = data.draw(
-            st.sampled_from(sorted(self.all_groups)), label="Group deletion target"
+            st.sampled_from(sorted(self.all_groups - {"", "/"})),
+            label="Group deletion target",
         )
         prefix, group_name = split_prefix_name(group_path)
         note(f"Deleting group '{group_path=!r}', {prefix=!r}, {group_name=!r} using delete")
@@ -358,9 +359,7 @@ def delete_group_using_del(self, data: DataObject) -> None:
             group = zarr.open_group(store=store, path=prefix)
             group[group_name]  # check that it exists
             del group[group_name]
-        if group_path != "/":
-            # The root group is always present
-            self.all_groups.remove(group_path)
+        self.all_groups.remove(group_path)
 
     # # --------------- assertions -----------------
     # def check_group_arrays(self, group):