APIClient format=json encodes bool values to strings

[mastacheata]

Hey there,

I'm trying to send a boolean value from a test using the APIClient from DRF and using the format=json parameter to auto-encode the payload to JSON.
When it arrives in the serializer's initial_data it's then automatically turned into a string. This does not happen when I send the request using JS or curl and manually encode the JSON to have a boolean value inside of a JSON object and it also doesn't occur when I set the content_type on the APIClient and encode the payload by hand using json.dumps instead.

Here's some simplified/reduced example code:

In the test I have this snippet:

payload = {
    'field': 'value',
    'skip_check': True,
}
self.client = APIClient()
response = self.client.post(reverse('api:some-api'), format='json', data=payload)

In the serializer, the skip_check field is not defined, but we access it from a field-level validation method (i.e. validate_field):

class SomeSerializer(ModelSerializer):
    class Meta:
        model = EmailUser
        fields = [
          'id',
          'field',
        ]

    def validate_email(self, email):
        logger = logging.getLogger('maklerpremium')
        logger.info(type(self.initial_data.get('skip_email_check', False)))  # Via Testcase: <class 'str'> / Via Frontend: <class 'bool'>
        logger.info(self.initial_data.get('skip_email_check', False)) # Via Testcase: True, Via Frontend: True

If instead of using format=json and passing the payload dictionary directly to the client.post method, I pass content_type='application/json' and encode the payload with json,dumps, everything behaves as expected (True is recognized as a boolean by the Serializer):

import json
payload = {
    'field': 'value',
    'skip_check': True,
}
self.client = APIClient()
response = self.client.post(reverse('api:account-list'),  content_type='application/json', data=json.dumps(payload))

I can't seem to find any reason why the built-in JSON Formatter might behave differently in this instance than the primitive json,dumps approach....