def test_from_file(self):
"""Test the `Config.from_file` class method.
Regression test for #3790: make sure configuration is written to disk after it is loaded and migrated.
"""
# If the config file does not exist, a completely new file is created with a migrated config
filepath_nonexisting = os.path.join(self.config_filebase,
'config_nonexisting.json')
config = Config.from_file(filepath_nonexisting)
# Make sure that the migrated config is written to disk, by loading it from disk and comparing to the content
# of the in memory config object.
self.compare_config_in_memory_and_on_disk(config, filepath_nonexisting)
# Now repeat the test for an existing file. The previous filepath now *does* exist and is migrated
filepath_existing = filepath_nonexisting
config = Config.from_file(filepath_existing)
self.compare_config_in_memory_and_on_disk(config, filepath_existing)
# Finally, we test that an existing configuration file with an outdated schema is migrated and written to disk
with tempfile.NamedTemporaryFile() as handle:
# Write content of configuration with old schema to disk
filepath = os.path.join(os.path.dirname(__file__), 'migrations',
'test_samples', 'input', '0.json')
with open(filepath, 'rb') as source:
handle.write(source.read())
handle.flush()
config = Config.from_file(handle.name)
self.compare_config_in_memory_and_on_disk(config, handle.name)
def test_from_file_no_migrate(self):
"""Test that ``Config.from_file`` does not overwrite if the content was not migrated."""
from time import sleep
# Construct the ``Config`` instance and write it to disk
Config(self.config_filepath, self.config_dictionary).store()
timestamp = os.path.getmtime(self.config_filepath)
Config.from_file(self.config_filepath)
# Sleep a second, because for some operating systems the time resolution is of the order of a second
sleep(1)
assert os.path.getmtime(self.config_filepath) == timestamp
