django-swagger-tester 1.0.0

Django test utility for validating Swagger documentation

Django Swagger Tester

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Documentation: https://django-swagger-tester.readthedocs.io

Repository: https://github.com/sondrelg/django-swagger-tester

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This package is a simple test utility for your Django Swagger documentation.

Its aim is to make it easy for developers to catch and correct documentation errors in their Swagger docs by comparing documented responses to actual API responses, or validating documented request bodies using actual input serializers.

Features

The package has three main features:

• Testing response documentation

• Testing input documentation

• Ensuring your docs comply with a single parameter naming standard.

  Supported naming standards include camelCase, snake_case, kebab-case, and PascalCase.

Implementations

We currently support testing of:

• Dynamically rendered Swagger docs, using drf_yasg

• All implementations which render Swagger docs from a schema file (yaml or json)

If you’re using another method to generate your documentation and would like to use this package, feel free to add an issue, or create a PR. Adding a new implementation is as easy as adding the required logic needed to load the OpenAPI schema.

Installation

Install using pip:

pip install django-swagger-tester

Configuration

Settings

To use Django Swagger Settings in your project, your first need to add a SWAGGER_TESTER object to your settings.py:

SWAGGER_TESTER = {
    'CASE': 'camel case',
    'PATH': BASE_DIR + '/openapi-schema.yml'  # not required for drf_yasg implementations
}

Parameters

CASE

The parameter naming standard you wish to enforce for your documentation.

Needs to be one of the following:

• camel case

• snake case

• pascal case

• kebab case

• None

Your OpenAPI schema will be assessed to make sure all parameter names are correctly cased according to this preference. If you do not wish to enforce this check, you can specify None to skip this feature.

Example:

SWAGGER_TESTER = {
    'CASE': 'snake case',
}

Default: camel case

PATH

The path to your OpenAPI specification.

Example:

SWAGGER_TESTER = {
    'PATH': BASE_DIR + '/openapi-schema.yml',
}

This setting is not required if your swagger docs are generated.

CAMEL_CASE_PARSER

Should be set to True if you use djangorestframework-camel-case’s CamelCaseJSONParser or CamelCaseJSONRenderer for your API views.

By settings this to True, example values constructed in the validate_input function will be snake cased before it’s passed to a serializer. See the function docs for more info.

Example:

SWAGGER_TESTER = {
    'CAMEL_CASE_PARSER': True,
}

Response Validation

To verify that your API response documentation is correct, we test the generated documentation against actual API responses.

A pytest implementation might look like this:

from django_swagger_tester.drf_yasg import validate_response  # or replace drf_yasg with `static_schema`


def test_response_documentation(client):
    response = client.get('api/v1/test/')

    assert response.status_code == 200
    assert response.json() == expected_response

    # Test Swagger documentation
    validate_response(response=response, method='GET', route='api/v1/test/')

A Django-test implementation might look like this:

class MyApiTest(APITestCase):

    def setUp(self) -> None:
        user, _ = User.objects.update_or_create(username='test_user')
        self.client.force_authenticate(user=user)
        self.path = '/api/v1/test/'

    def test_get_200(self) -> None:
        """
        Verifies that a 200 is returned for a valid GET request to the /test/ endpoint.
        """
        response = self.client.get(self.path, headers={'Content-Type': 'application/json'})
        expected_response = [...]

        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.json(), expected_response)

        # Test Swagger documentation
        validate_response(response=response, method='GET', route=self.path)

You can also test more than a single response at the time:

def test_response_documentation(client):
    # 201 - Resource created
    response = client.post('api/v1/test/', data=...)
    validate_response(response=response, method='POST', route='api/v1/test/')

    # 200 - Idempotency --> if an object exists, return it with a 200 without creating a new resource
    response = client.post('api/v1/test/', data=...)
    validate_response(response=response, method='POST', route='api/v1/test/')

    # 400 - Bad data
    response = client.post('api/v1/test/', data=bad_data)
    validate_response(response=response, method='POST', route='api/v1/test/')

Input Validation

To make sure your request body documentation is accurate, and will stay accurate, it can be useful to set up tests.

Considering most APIs will use input serializers for input validation, it seems sensible to just run the example documentation on your serializer.

A pytest implementation of input validation might look like this:

from myapp.api.serializers import MyAPISerializer  # <-- your custom serializer


def test_request_body_documentation(client):
    """
    Verifies that our request body documentation is representative of a valid request body.
    """
    from django_swagger_tester.drf_yasg import validate_input  # or replace drf_yasg with `static_schema`
    validate_input(serializer=MyAPISerializer, method='POST', route='api/v1/test/', camel_case_parser=True)

The camel_case_parser argument should be set to True if you are using CamelCaseJSONParser or CamelCaseJSONRenderer from the djangorestframework-camel-case package.