`delete_downstream_merge` should capture all parts with fk-refs

[MichaelCoulter]

im trying to run this command:

(Nwbfile & {'nwb_file_name':'BS2820231107_.nwb'}).delete()

and i get this error:

Error stack

---------------------------------------------------------------------------
NetworkXError                             Traceback (most recent call last)
File ~/spyglass/src/spyglass/utils/dj_mixin.py:237, in SpyglassMixin._merge_tables(self)
    236 try:
--> 237     _ = search_descendants(self)
    238 except NetworkXError as e:

File ~/spyglass/src/spyglass/utils/dj_mixin.py:234, in SpyglassMixin._merge_tables.<locals>.search_descendants(parent)
    233 visited.add(master_name)
--> 234 search_descendants(master_ft)

File ~/spyglass/src/spyglass/utils/dj_mixin.py:222, in SpyglassMixin._merge_tables.<locals>.search_descendants(parent)
    217 def search_descendants(parent):
    218     # TODO: Add check that parents are in the graph. If not, raise error
    219     #       asking user to import the table.
    220     # TODO: Make a `is_merge_table` helper, and check for false
    221     #       positives in the mixin init.
--> 222     for desc in parent.descendants(as_objects=True):
    223         if (
    224             MERGE_PK not in desc.heading.names
    225             or not (master_name := get_master(desc.full_table_name))
    226             or master_name in merge_tables
    227         ):

File ~/anaconda3/envs/spyglass2/lib/python3.9/site-packages/datajoint/table.py:212, in Table.descendants(self, as_objects)
    205 """
    206 
    207 :param as_objects: False - a list of table names; True - a list of table objects.
    208 :return: list of tables descendants in topological order.
    209 """
    210 return [
    211     FreeTable(self.connection, node) if as_objects else node
--> 212     for node in self.connection.dependencies.descendants(self.full_table_name)
    213     if not node.isdigit()
    214 ]

File ~/anaconda3/envs/spyglass2/lib/python3.9/site-packages/datajoint/dependencies.py:170, in Dependencies.descendants(self, full_table_name)
    169 self.load(force=False)
--> 170 nodes = self.subgraph(nx.algorithms.dag.descendants(self, full_table_name))
    171 return unite_master_parts(
    172     [full_table_name] + list(nx.algorithms.dag.topological_sort(nodes))
    173 )

File ~/anaconda3/envs/spyglass2/lib/python3.9/site-packages/networkx/algorithms/dag.py:53, in descendants(G, source)
     52 if not G.has_node(source):
---> 53     raise nx.NetworkXError(f"The node {source} is not in the graph.")
     54 des = {n for n, d in nx.shortest_path_length(G, source=source).items()}

NetworkXError: The node `position_linearization_merge`.`linearized_position_output` is not in the graph.

During handling of the above exception, another exception occurred:

ValueError                                Traceback (most recent call last)
Cell In [4], line 1
----> 1 (Nwbfile & {'nwb_file_name':'BS2820231107_.nwb'}).delete()

File ~/spyglass/src/spyglass/utils/dj_mixin.py:587, in SpyglassMixin.delete(self, force_permission, *args, **kwargs)
    585 def delete(self, force_permission=False, *args, **kwargs):
    586     """Alias for cautious_delete, overwrites datajoint.table.Table.delete"""
--> 587     self.cautious_delete(force_permission=force_permission, *args, **kwargs)

File ~/spyglass/src/spyglass/utils/dj_mixin.py:550, in SpyglassMixin.cautious_delete(self, force_permission, *args, **kwargs)
    547 if not force_permission:
    548     self._check_delete_permission()
--> 550 merge_deletes = self.delete_downstream_merge(
    551     dry_run=True,
    552     disable_warning=True,
    553     return_parts=False,
    554 )
    556 safemode = (
    557     dj.config.get("safemode", True)
    558     if kwargs.get("safemode") is None
    559     else kwargs["safemode"]
    560 )
    562 if merge_deletes:

File ~/spyglass/src/spyglass/utils/dj_mixin.py:339, in SpyglassMixin.delete_downstream_merge(self, restriction, dry_run, reload_cache, disable_warning, return_parts, **kwargs)
    336 restriction = restriction or self.restriction or True
    338 merge_join_dict = {}
--> 339 for name, chain in self._merge_chains.items():
    340     join = chain.join(restriction)
    341     if join:

File ~/anaconda3/envs/spyglass2/lib/python3.9/functools.py:993, in cached_property.__get__(self, instance, owner)
    991 val = cache.get(self.attrname, _NOT_FOUND)
    992 if val is _NOT_FOUND:
--> 993     val = self.func(instance)
    994     try:
    995         cache[self.attrname] = val

File ~/spyglass/src/spyglass/utils/dj_mixin.py:262, in SpyglassMixin._merge_chains(self)
    251 """Dict of chains to merges downstream of self
    252 
    253 Format: {full_table_name: TableChains}.
   (...)
    259 delete_downstream_merge call.
    260 """
    261 merge_chains = {}
--> 262 for name, merge_table in self._merge_tables.items():
    263     chains = TableChains(self, merge_table, connection=self.connection)
    264     if len(chains):

File ~/anaconda3/envs/spyglass2/lib/python3.9/functools.py:993, in cached_property.__get__(self, instance, owner)
    991 val = cache.get(self.attrname, _NOT_FOUND)
    992 if val is _NOT_FOUND:
--> 993     val = self.func(instance)
    994     try:
    995         cache[self.attrname] = val

File ~/spyglass/src/spyglass/utils/dj_mixin.py:240, in SpyglassMixin._merge_tables(self)
    238 except NetworkXError as e:
    239     table_name = "".join(e.args[0].split("`")[1:4])
--> 240     raise ValueError(f"Please import {table_name} and try again.")
    242 logger.info(
    243     f"Building merge cache for {self.table_name}.\n\t"
    244     + f"Found {len(merge_tables)} downstream merge tables"
    245 )
    247 return merge_tables

ValueError: Please import position_linearization_merge.linearized_position_output and try again.

any help is appreciated. thanks.