# Copyright (c) 2018 Alexander Todorov <atodorov@MrSenko.com>
# Licensed under the GPL 2.0: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint-django/blob/master/LICENSE
"""
Various suggestions about JSON http responses
"""
import astroid
from pylint import checkers, interfaces
from pylint.checkers import utils
from pylint_django.__pkginfo__ import BASE_ID
class JsonResponseChecker(checkers.BaseChecker):
"""
Looks for some common patterns when returning http responses containing
JSON data!
"""
__implements__ = (interfaces.IAstroidChecker,)
# configuration section name
name = "json-response-checker"
msgs = {
f"R{BASE_ID}01": (
"Instead of HttpResponse(json.dumps(data)) use JsonResponse(data)",
"http-response-with-json-dumps",
"Used when json.dumps() is used as an argument to HttpResponse().",
),
f"R{BASE_ID}02": (
"Instead of HttpResponse(content_type='application/json') use JsonResponse()",
"http-response-with-content-type-json",
"Used when HttpResponse() is returning application/json.",
),
f"R{BASE_ID}03": (
"Redundant content_type parameter for JsonResponse()",
"redundant-content-type-for-json-response",
"Used when JsonResponse() contains content_type parameter. "
"This is either redundant or the content_type is not JSON "
"which is probably an error.",
),
}
@utils.check_messages(
"http-response-with-json-dumps",
"http-response-with-content-type-json",
"redundant-content-type-for-json-response",
)
def visit_call(self, node):
if (
node.func.as_string().endswith("HttpResponse")
and node.args
and isinstance(node.args[0], astroid.Call)
and node.args[0].func.as_string() == "json.dumps"
):
self.add_message("http-response-with-json-dumps", node=node)
if node.func.as_string().endswith("HttpResponse") and node.keywords:
for keyword in node.keywords:
if keyword.arg == "content_type" and keyword.value.as_string().lower().find("application/json") > -1:
self.add_message("http-response-with-content-type-json", node=node)
break
if node.func.as_string().endswith("JsonResponse") and node.keywords:
for keyword in node.keywords:
if keyword.arg == "content_type":
self.add_message("redundant-content-type-for-json-response", node=node)
break
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