Mini Shell

# 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