abort: Why is data conditionally added?

[sloria]

flask-restful/flask_restful/__init__.py

Lines 34 to 35 in 8c8c727

	if len(kwargs):
	e.data = kwargs

Why check len(kwargs) here? This requires handling code to check for the existence of the data attribute:

    if hasattr(error, data):
        error.data.get(my_kwarg, default_val)

Can the check be removed?

For context: webargs has a similar abort function, and this issue came up in a PR: marshmallow-code/webargs#184 . I think it's a good idea to remove the check. Before I merge that, though, I thought I'd ask about the original rationale.

[joshfriend]

Not sure TBH, but the error handler adds a default data value if one doesn't exist:

flask-restful/flask_restful/__init__.py

Line 312 in 16be48b

data = getattr(e, 'data', default_data)

If you remove it do the tests still pass?

[sloria]

@joshfriend

No, this test fails.

flask-restful/tests/test_api.py

Lines 753 to 758 in 16be48b

	def test_abort_no_data(self):
	try:
	flask_restful.abort(404)
	assert False # We should never get here
	except Exception as e:
	self.assertEquals(False, hasattr(e, "data"))

Though if you need to check if data were passed, you could just do

data = e.data or default_data