Adding best practices and assertion checks to workflow_lint

[simonbray]

Fixes #1178, #1181, #1211

[simonbray]

maybe this can be improved, if someone knows more about importing Python functions than me?

[mvdbeek]

You could check that this is a function with https://docs.python.org/3/library/inspect.html#inspect.isfunction
and inspect the signature with https://docs.python.org/3/library/inspect.html#inspect.signature instead of relying on TypeError. OTOH that's some manual parsing that is maybe not necessary. A healthy middleground could be to run https://docs.python.org/3/library/inspect.html#inspect.Signature.bind, so we don't have to execute the test function.

[simonbray]

run https://docs.python.org/3/library/inspect.html#inspect.Signature.bind, so we don't have to execute the test function.

That is cool, thanks!

[mvdbeek]

Really cool, thanks for all the tests!

[simonbray]

Suggested change

	for function_name in dir(module):
	if function_name.split('assert_')[-1] in assertion_definitions:
	signature = inspect.signature(module.__dict__[function_name])
	try:
	# try mapping the function with the attributes supplied and check for TypeError
	signature.bind('', **assertion_definitions[function_name.split('assert_')[-1]])
	except AssertionError:
	pass
	except TypeError as e:
	lint_context.error(f'Invalid assertion in tests: {function_name} {str(e)}')
	assertions_valid = False
	for function_name, function in asserts.assertion_functions.items():
	if function_name.split('assert_')[-1] in assertion_definitions:
	signature = inspect.signature(function)
	try:
	# try mapping the function with the attributes supplied and check for TypeError
	signature.bind('', **assertion_definitions[function_name.split('assert_')[-1]])
	except AssertionError:
	pass
	except TypeError as e:
	lint_context.error(f'Invalid assertion in tests: {function_name} {str(e)}')
	assertions_valid = False

When galaxyproject/galaxy#12528 is incorporated into a published version of galaxy-tool-util this change will be needed.