def test_dependents_list_is_created_by_instrument(file): # noqa: F811
"""
The dependents list for transforms is stored in the "dependent_of" attribute,
which is not part of the NeXus standard,
we therefore cannot rely on it being present and correct in a file we load.
This test makes sure that instrument generates this information in the wrapped NeXus file it is given.
"""
# Create minimal test file with some transformations but no "dependent_of" attributes
entry_group = file.create_group("entry")
entry_group.attrs["NX_class"] = "NXentry"
instrument_group = entry_group.create_group("instrument")
instrument_group.attrs["NX_class"] = "NXinstrument"
transforms_group = instrument_group.create_group("transformations")
transforms_group.attrs["NX_class"] = "NXtransformations"
transform_1 = transforms_group.create_dataset("transform_1", data=42)
transform_2 = transforms_group.create_dataset("transform_2", data=42)
transform_3 = transforms_group.create_dataset("transform_3", data=42)
transform_4 = transforms_group.create_dataset("transform_4", data=42)
transform_2.attrs["depends_on"] = transform_1.name
transform_3.attrs["depends_on"] = transform_2.name
transform_4.attrs["depends_on"] = transform_2.name
nexus_wrapper = NexusWrapper("test_file_with_transforms")
nexus_wrapper.load_file(entry_group, file)
Instrument(nexus_wrapper, NX_CLASS_DEFINITIONS)
transform_1_loaded = Transformation(nexus_wrapper, transform_1)
assert (
len(transform_1_loaded.get_dependents()) == 1
), "Expected transform 1 to have a registered dependent (transform 2)"
transform_2_loaded = Transformation(nexus_wrapper, transform_2)
assert (
len(transform_2_loaded.get_dependents()) == 2
), "Expected transform 2 to have 2 registered dependents (transforms 3 and 4)"
def remove_transformation(self, transform: Transformation):
if not self._transform_is_in_this_component(transform):
raise PermissionError(
"Transform is not in this component, do not have permission to delete"
)
dependents = transform.get_dependents()
if dependents:
raise DependencyError(
f"Cannot delete transformation, it is a dependency of {dependents}"
)
# Remove whole transformations group if this is the only transformation in it
if len(transform._dataset.parent.keys()) == 1:
self.file.delete_node(transform._dataset.parent)
# Otherwise just remove the transformation from the group
else:
self.file.delete_node(transform._dataset)
