DRF OpenAPI Tester

DRF OpenAPI Tester is a test utility to validate API responses against OpenAPI 2 and 3 schema. It has built-in support for:

• OpenAPI 2/3 yaml or json schema files.
• OpenAPI 2 schemas created with drf-yasg.
• OpenAPI 3 schemas created with drf-spectacular.

Installation

pip install drf-openapi-tester

Usage

First instantiate one or more instances of SchemaTester:

from openapi_tester import SchemaTester

schema_tester = SchemaTester()

If you are using either drf-yasg or drf-spectacular this will be auto-detected, and the schema will be loaded by the SchemaTester automatically. If you are using schema files though, you will need to pass the file path to the tester:

from openapi_tester import SchemaTester

# path should be a string
schema_tester = SchemaTester(schema_file_path="./schemas/publishedSpecs.yaml")

Once you instantiate a tester, you can use it to validate a DRF Response in a test:

from openapi_tester.schema_tester import SchemaTester

# you need to create at least one instance of SchemaTester.
# you can pass kwargs to it
schema_tester = SchemaTester()


def test_response_documentation(client):
    response = client.get('api/v1/test/1')
    assert response.status_code == 200
    schema_tester.validate_response(response=response)

If you are using the Django testing framework, you can create a base APITestCase that incorporates schema validation:

from openapi_tester.schema_tester import SchemaTester
from rest_framework.test import APITestCase
from rest_framework.response import Response

schema_tester = SchemaTester()


class BaseAPITestCase(APITestCase):
    """ Base test class for api views including schema validation """

    @staticmethod
    def assertResponse(response: Response, **kwargs) -> None:
        """ helper to run validate_response and pass kwargs to it """
        schema_tester.validate_response(response=response, **kwargs)

Then use it in a test file:

from shared.testing import BaseAPITestCase


class MyAPITests(BaseAPITestCase):
    def test_some_view(self):
        response = self.client.get("...")
        self.assertResponse(response)

Options

We currently support the following optional kwargs:

Case tester

The case tester argument takes a callable to validate the case of both your response schemas and responses. If nothing is passed, case validation is skipped.

The library currently has 4 build-in functions that can be used:

• is_pascal_case
• is_snake_case
• is_camel_case
• is_kebab-case

for example:

from openapi_tester import SchemaTester, is_camel_case

schema_test_with_case_validation = SchemaTester(case_tester=is_camel_case)

or

from openapi_tester import SchemaTester, is_camel_case

schema_tester = SchemaTester()


def my_test(client):
    response = client.get('api/v1/test/1')
    assert response.status_code == 200
    schema_tester.validate_response(response=response, case_tester=is_camel_case)

You of course pass your own custom validator function.

Ignore case

List of keys to ignore. In some cases you might want to declare a global list of keys exempt from case testing.

for example:

from openapi_tester import SchemaTester, is_camel_case

schema_test_with_case_validation = SchemaTester(case_tester=is_camel_case, ignore_case=["IP"])

Schema Validation

When the SchemaTester loads a schema, it runs it through OpenAPI Spec validator which validates that the schema passes without specification compliance issues. In case of issues the validator will raise an error.

Known Issues

• We are using prance as a schema resolver, and it has some issues with the resolution of (very) complex OpenAPI 2.0 schemas. If you encounter issues, please document them here.

Contributing

Contributions are welcome. Please see the contributing guide