pact-python manages the mock service for the user

- Extracted the logic configuring the mock service and verifying interactions to methods
  for users if they need more control than a context manager provides

Author: matthewbalvanz-wf

README.md

@@ -47,8 +47,8 @@ from pact import Consumer, Provider
 
 
 pact = Consumer('Consumer').has_pact_with(Provider('Provider'))
-pact.start()
-atexit.register(pact.stop)
+pact.start_service()
+atexit.register(pact.stop_service)
 
 
 class GetUserInfoContract(unittest.TestCase):
@@ -82,7 +82,22 @@ This does a few important things:
 Using the Pact object as a [context manager], we call our method under test
 which will then communicate with the Pact mock service. The mock service will respond with
 the items we defined, allowing us to assert that the method processed the response and
-returned the expected value.
+returned the expected value. If you want more control over when the mock service is 
+configured and the interactions verified, use the `setup` and `verify` methods, respectively:
+
+```python
+   (pact
+     .given('UserA exists and is not an administrator')
+     .upon_receiving('a request for UserA')
+     .with_request('get', '/users/UserA')
+     .will_respond_with(200, body=expected))
+
+    pact.setup()
+    # Some additional steps before running the code under test
+    result = user('UserA')
+    # Some additional steps before verifying all interactions have occurred
+    pact.verify()
+````
 
 The default hostname and port for the Pact mock service will be
 `localhost:1234` but you can adjust this during Pact creation:

e2e/contracts/test_e2e.py

@@ -9,8 +9,8 @@
 
 
 pact = Consumer('consumer').has_pact_with(Provider('provider'))
-pact.start()
-atexit.register(pact.stop)
+pact.start_service()
+atexit.register(pact.stop_service)
 
 
 class BaseTestCase(unittest.TestCase):

pact/pact.py

@@ -106,7 +106,29 @@ def given(self, provider_state):
         self._provider_state = provider_state
         return self
 
-    def start(self):
+    def setup(self):
+        """Configure the Mock Service to ready it for a test."""
+        try:
+            payload = {
+                'description': self._description,
+                'provider_state': self._provider_state,
+                'request': self._request,
+                'response': self._response
+            }
+
+            resp = requests.delete(
+                self.uri + '/interactions', headers=self.HEADERS)
+
+            assert resp.status_code == 200, resp.content
+            resp = requests.post(
+                self.uri + '/interactions',
+                headers=self.HEADERS, json=payload)
+
+            assert resp.status_code == 200, resp.content
+        except AssertionError:
+            raise
+
+    def start_service(self):
         """Start the external Mock Service."""
         command = [
             MOCK_SERVICE_PATH,
@@ -131,7 +153,7 @@ def start(self):
         if process.returncode != 0:
             raise RuntimeError('The Pact mock service failed to start.')
 
-    def stop(self):
+    def stop_service(self):
         """Stop the external Mock Service."""
         command = [MOCK_SERVICE_PATH, 'stop', '--port={}'.format(self.port)]
         popen = Popen(command)
@@ -151,6 +173,28 @@ def upon_receiving(self, scenario):
         self._description = scenario
         return self
 
+    def verify(self):
+        """
+        Have the mock service verify all interactions occurred.
+
+        Calls the mock service to verify that all interactions occurred as
+        expected, and has it write out the contracts to disk.
+
+        :raises AssertionError: When not all interactions are found.
+        """
+        resp = requests.get(
+            self.uri + '/interactions/verification',
+            headers=self.HEADERS)
+        assert resp.status_code == 200, resp.content
+        payload = {
+            'consumer': {'name': self.consumer.name},
+            'provider': {'name': self.provider.name},
+            'pact_dir': self.pact_dir
+        }
+        resp = requests.post(
+            self.uri + '/pact', headers=self.HEADERS, json=payload)
+        assert resp.status_code == 200, resp.content
+
     def with_request(self, method, path, body=None, headers=None, query=None):
         """
         Define the request the request that the client is expected to perform.
@@ -198,25 +242,7 @@ def __enter__(self):
 
         Sets up the mock service to expect the client requests.
         """
-        try:
-            payload = {
-                'description': self._description,
-                'provider_state': self._provider_state,
-                'request': self._request,
-                'response': self._response
-            }
-
-            resp = requests.delete(
-                self.uri + '/interactions', headers=self.HEADERS)
-
-            assert resp.status_code == 200, resp.content
-            resp = requests.post(
-                self.uri + '/interactions',
-                headers=self.HEADERS, json=payload)
-
-            assert resp.status_code == 200, resp.content
-        except AssertionError:
-            raise
+        self.setup()
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         """
@@ -228,18 +254,7 @@ def __exit__(self, exc_type, exc_val, exc_tb):
         if (exc_type, exc_val, exc_tb) != (None, None, None):
             return
 
-        resp = requests.get(
-            self.uri + '/interactions/verification',
-            headers=self.HEADERS)
-        assert resp.status_code == 200, resp.content
-        payload = {
-            'consumer': {'name': self.consumer.name},
-            'provider': {'name': self.provider.name},
-            'pact_dir': self.pact_dir
-        }
-        resp = requests.post(
-            self.uri + '/pact', headers=self.HEADERS, json=payload)
-        assert resp.status_code == 200, resp.content
+        self.verify()
 
 
 class FromTerms(object):