Mock services
Aims to provide an easy way to mock an entire service API based on requests-mock and a simple dict definition of a service. The idea is to mock everything at start according given rules. Then mock-services allows to start/stop http mock locally.
During our session we can:
- add rules
- permit external calls
- stop mocking
- reset rules
- restart mocking
- etc.
Mock endpoints explicitly
Note: rules urls must be regex. They always will be compiled before updating the main requests-mock urls registry.
Let's mock our favorite search engine:
>>> def fake_duckduckgo_cb(request):
... return 200, {}, 'Coincoin!'
>>> rules = [
... {
... 'text': fake_duckduckgo_cb,
... 'headers': {'Content-Type': 'text/html'},
... 'method': 'GET',
... 'url': r'^https://duckduckgo.com/\?q='
... },
... ]
>>> from mock_services import update_http_rules
>>> update_http_rules(rules)
>>> import requests
>>> requests.get('https://duckduckgo.com/?q=mock-services').content[:15]
'<!DOCTYPE html>'
>>> from mock_services import start_http_mock
>>> start_http_mock()
>>> requests.get('https://duckduckgo.com/?q=mock-services').content
'Coincoin!'
When the http_mock is started if you try to call an external url, it should fail:
>>> requests.get('https://www.google.com/#q=mock-services')
...
ConnectionError: Connection refused: GET https://www.google.com/#q=mock-services
Then you can allow external calls if needed:
>>> from mock_services import http_mock
>>> http_mock.set_allow_external(True)
>>> requests.get('https://www.google.com/#q=mock-services').content[:15]
'<!doctype html>'
At anytime you can stop the mocking as follow:
>>> from mock_services import stop_http_mock
>>> stop_http_mock()
>>> requests.get('https://duckduckgo.com/?q=mock-services').content[:15]
'<!DOCTYPE html>'
Or stop mocking during a function call:
>>> start_http_mock()
>>> @no_http_mock
... def please_do_not_mock_me():
... return requests.get('https://duckduckgo.com/?q=mock-services').content[:15] == '<!DOCTYPE html>', 'mocked!'
>>> please_do_not_mock_me
Or start mocking for another function call:
>>> stop_http_mock()
>>> @with_http_mock
... def please_mock_me():
... assert requests.get('https://duckduckgo.com/?q=mock-services').content == 'Coincoin', 'no mock!'
>>> please_mock_me
Mock service easy
You can add REST rules with an explicit method. It will add rules as above and automatically bind callbacks to fake a REST service.
Note: resource and id regex options are mandatory in the rules urls.
Additionally, `mock_services`_ include attrs library. It can be use for field validation as follow.
This service mock will create, get, update and delete resources for you:
>>> import attr
>>> rest_rules = [
... {
... 'method': 'LIST',
... 'url': r'^http://my_fake_service/(?P<resource>api)$'
... },
... {
... 'method': 'GET',
... 'url': r'^http://my_fake_service/(?P<resource>api)/(?P<id>\d+)$',
... },
... {
... 'method': 'GET',
... 'url': r'^http://my_fake_service/(?P<resource>api)/(?P<id>\d+)/(?P<action>download)$',
... },
... {
... 'method': 'POST',
... 'url': r'^http://my_fake_service/(?P<resource>api)$',
... 'id_name': 'id',
... 'id_factory': int,
... 'attrs': {
... 'bar': attr.ib(),
... 'foo':attr.ib(default=True)
... }
... },
... {
... 'method': 'PATCH',
... 'url': r'^http://my_fake_service/(?P<resource>api)/(?P<id>\d+)$',
... },
... {
... 'method': 'DELETE',
... 'url': r'^http://my_fake_service/(?P<resource>api)/(?P<id>\d+)$'
... },
... ]
>>> from mock_services import update_rest_rules
>>> update_rest_rules(rest_rules)
>>> from mock_services import start_http_mock
>>> start_http_mock()
>>> response = requests.get('http://my_fake_service/api')
>>> response.status_code
200
>>> response.json()
[]
>>> response = requests.get('http://my_fake_service/api/1')
>>> response.status_code
404
>>> import json
>>> response = requests.post('http://my_fake_service/api',
... data=json.dumps({}),
... headers={'content-type': 'application/json'})
>>> response.status_code
400
>>> response = requests.post('http://my_fake_service/api',
... data=json.dumps({'bar': 'Python will save the world'}),
... headers={'content-type': 'application/json'})
>>> response.status_code
201
>>> response.json()
{
'id': 1,
'foo'; True,
'bar'; 'Python will save the world.'
}
>>> response = requests.patch('http://my_fake_service/api/1',
... data=json.dumps({'bar': "Python will save the world. I don't know how. But it will."}),
... headers={'content-type': 'application/json'})
>>> response.status_code
200
>>> response = requests.get('http://my_fake_service/api/1')
>>> response.status_code
200
>>> response.json()
{
'id': 1,
'foo'; True,
'bar'; "Python will save the world. I don't know how. But it will."
}
>>> response = requests.delete('http://my_fake_service/api/1')
>>> response.status_code
204
More validation
Is some cases you need to validate a resource against another. Then you can add global validators per endpoint as follow:
>>> from mock_services import storage
>>> from mock_services.service import ResourceContext
>>> from mock_services.exceptions import Http409
>>> def duplicate_foo(request):
... data = json.loads(request.body)
... ctx = ResourceContext(hostname='my_fake_service', resource='api')
... if data['foo'] in [o['foo'] for o in storage.list(ctx)]:
... raise Http409
>>> rest_rules_with_validators = [
... {
... 'method': 'POST',
... 'url': r'^http://my_fake_service/(?P<resource>api)$',
... 'validators': [
... duplicate_foo,
... ],
... },
... ]
>>> response = requests.post('http://my_fake_service/api',
... data=json.dumps({'foo': 'bar'}),
... headers={'content-type': 'application/json'})
>>> response.status_code
201
>>> response = requests.post('http://my_fake_service/api',
... data=json.dumps({'foo': 'bar'}),
... headers={'content-type': 'application/json'})
>>> response.status_code
409
Have fun in testing external APIs ;)
