Merge pull request #19 from ShipChain/feature/httpretty-asserter-mixin

Modify HTTPretty to allow for assertion testing

Author: ajhodges

README.md

@@ -190,3 +190,45 @@ json_asserter.HTTP_200(response,
 If there is a class where every test may wish to use the `json_asserter`, than it may be easier to use to the `JsonAsserterMixin` found in `shipchain_common.test_utils`.
 This will automatically add the `json_asserter` and set it as a class attribute before the tests are run.
 This allows you to just call `self.json_asserter`, allowing for cleaner unit tests imports. 
+
+
+### HTTPrettyAsserter Usage
+
+When mocking calls, this can help in ensuring all calls, and only those, were made as expected, with the desired parameters.
+In order to use, simply import the HTTPrettyAsserter from test_utils and use it in place of the usual httpretty:
+```python
+@pytest.yield_fixture
+def modified_http_pretty():
+    HTTPrettyAsserter.enable(allow_net_connect=False)
+    yield HTTPrettyAsserter
+    HTTPrettyAsserter.disable()
+```
+
+Then, you just need to register the uris for the calls you want to mock, and ensure that it is returned in the mocking:
+```python
+@pytest.fixture
+def http_pretty_list_mocking(modified_http_pretty):
+    modified_http_pretty.register_uri(modified_http_pretty.POST, 'http://google.com/path', status=status.HTTP_200_OK)
+    modified_http_pretty.register_uri(modified_http_pretty.POST, 'http://google.com/other_path',
+                                      status=status.HTTP_200_OK)
+    modified_http_pretty.register_uri(modified_http_pretty.POST, 'http://bing.com/bing_path',
+                                      status=status.HTTP_200_OK)
+    return modified_http_pretty
+```
+
+In a test that you want to check the calls on, you simply need to use the mocking fixture and call `.assert_calls(assertions)` on the fixture.
+These assertions will be a list of details that the call should have made. An example assertion is this:
+```python
+{
+    'path': '/path',
+    'body': {
+        'integer': 1      
+    },
+    'query': {
+        'query_param_1': 1
+    },
+    'host': 'google.com',
+}
+```
+ Only the path and the host are required parameters for the assertion. The body and query can be left out, but if included will be tested against.
+ If there is a difference between the amount of calls made and the amount of assertions, no assertion will be made and instead an error will return.