def test_mappings(model_name, config):
"""
Test that `MAPPINGS` includes all the data necessary for covering all the cases.
This is to avoid missing tests when new fields and models are added or changed.
"""
model = apps.get_model(model_name)
try:
mapping = MAPPINGS[model_name]
except KeyError:
pytest.fail(f'Please add test cases for deleting orphaned {model}')
related_fields = get_related_fields(model)
expected_related_deps = {(field.field.model, field.field.name)
for field in related_fields
if field not in config.excluded_relations}
related_deps_in_mapping = {
(dep_factory._meta.model, dep_field_name)
for dep_factory, dep_field_name in mapping['dependent_models']
}
ignored_relations = {
(apps.get_model(model_label), field_name)
for model_label, field_name in mapping['ignored_models']
}
missing_dep_mappings = expected_related_deps - related_deps_in_mapping - ignored_relations
if missing_dep_mappings:
dep_list = [
f'{model}.{field}' for model, field in missing_dep_mappings
]
error_msg = (
f'Please add tests for not deleting {model} when the following '
f'fields reference it: {", ".join(dep_list)}')
assert not missing_dep_mappings, error_msg
def test_configs(model_label, config):
"""
Test that configs for delete_old_records cover all relations for the model.
This is to make sure any new relations that are added are not missed from the
configurations.
"""
model = apps.get_model(model_label)
related_fields = get_related_fields(model)
field_missing_from_config = (
set(related_fields) - (config.relation_filter_mapping or {}).keys() -
set(config.excluded_relations))
fields_for_error_message = '\n'.join(
(_format_field(field) for field in field_missing_from_config), )
assert not field_missing_from_config, (
f'The following related fields are missing from the config for {model_label}:\n'
f'{fields_for_error_message}.\n'
f'\n'
f' Please add them to the ModelCleanupConfig in either '
f'relation_filter_mapping or excluded_relations.\n'
f'\n'
f'Only add the model to excluded_relations if its existence should not affect '
f'whether {model_label} objects are be deleted. You can specify an empty filter '
f'list in relation_filter_mapping if they should not be filtered.\n'
f'\n'
f'See ModelCleanupConfig and the delete_old_records command for more details.'
)
def get_unreferenced_objects_query(
model,
excluded_relations=(),
relation_exclusion_filter_mapping=None,
):
"""
Generates a query set of unreferenced objects for a model.
:param model: the model to generate a query set of unreferenced objects
:param excluded_relations: related fields on model that should be ignored
:param relation_exclusion_filter_mapping:
Optional mapping of relations (fields on model) to Q objects.
For each relation where a Q object is provided, the Q object is used to exclude
objects for that relation prior to checking if any references to the model exist (for
that relation).
Example:
This example will not consider interactions dated before 2015-01-01 when getting
unreferenced companies.
get_unreferenced_objects_query(
Company,
relation_exclusion_filter_mapping={
Company._meta.get_field('interactions'): Q(date__lt=date(2015, 1, 1),
}
)
:returns: queryset for unreferenced objects
"""
if relation_exclusion_filter_mapping is None:
relation_exclusion_filter_mapping = {}
fields = set(get_related_fields(model)) - set(excluded_relations)
identifiers = [f'ann_{token_urlsafe(6)}' for _ in range(len(fields))]
if relation_exclusion_filter_mapping.keys() - fields:
raise ValueError(
'Invalid fields detected in relation_exclusion_filter_mapping.')
qs = model.objects.all()
for identifier, field in zip(identifiers, fields):
related_field = field.field
exclusion_filters = relation_exclusion_filter_mapping.get(field, Q())
subquery = related_field.model.objects.filter(
**{
related_field.attname: OuterRef('pk')
}, ).exclude(exclusion_filters, ).only('pk')
qs = qs.annotate(**{identifier: Exists(subquery)})
filter_args = {identifier: False for identifier in identifiers}
return qs.filter(**filter_args)
def is_company_a_valid_merge_source(company: Company):
"""Checks if company can be moved."""
# First, check that there are no references to the company from other objects
# (other than via the fields specified in ALLOWED_RELATIONS_FOR_MERGING).
relations = get_related_fields(Company)
has_related_objects = any(
getattr(company, relation.name).count() for relation in relations
if relation.remote_field not in ALLOWED_RELATIONS_FOR_MERGING)
if has_related_objects:
return False
# Then, check that the source company itself doesn't have any references to other
# companies.
self_referential_fields = get_self_referential_relations(Company)
return not any(
getattr(company, field.name) for field in self_referential_fields)