Unexpected Behavior: 500 Internal Server Error unhandled by PyCap

[angus-lherrou]

Describe the behavior:

When a request is made with PyCap that results in a 500 Internal Server Error response, PyCap's _RCRequest.get_content does not handle this error; instead, with format_type="csv"|"xml", an empty string from response.text is silently returned, and with format_type="json", a requests.exceptions.JSONDecodeError('Expecting value: line 1 column 1 (char 0)') is raised due to response.text being an empty string.

Expected behavior:

The expected behavior would be to detect a 500 code in the request response and emit an informative error from get_content.

Desktop:

• OS: Ubuntu 20.04.5 LTS x86_64
• REDCap version 12.4.7
• PyCap Version 2.4.0

[pwildenhain]

Thanks for raising the issue -- what is the body of the response that PyCap fails to capture -- i.e what error message shows for a 500 response?

[angus-lherrou]

@pwildenhain response.text is an empty string and response.reason is 'Internal Server Error'.

[pwildenhain]

Got it!

Looks like this piece of the code needs to be updated:

PyCap/redcap/request.py

Lines 196 to 209 in a507d1a

	if self.fmt == "json":
	try:
	bad_request = "error" in content.keys() # type: ignore
	except AttributeError:
	# we're not dealing with an error dict
	bad_request = False
	elif self.fmt == "csv":
	bad_request = content.lower().startswith("error:") # type: ignore
	# xml is the default returnFormat for error messages
	elif self.fmt == "xml" or self.fmt is None:
	bad_request = "<error>" in str(content).lower()
	if bad_request:
	raise RedcapError(content)

We should check the status code to see if it's 500 (or one of it's variants?), and if so, then raise RedcapError(response.reason). We can probably add this check before/after the if block that checks the content for a bad_request

Would you be open to making this contribution? See here for what that might entail: https://github.com/redcap-tools/PyCap/blob/master/CONTRIBUTING.md

[angus-lherrou]

Happy to open a PR.