Make cassette active for duration of coroutine/generator

Closes #177.

tests/integration/test_tornado.py

@@ -275,3 +275,12 @@ def test_cannot_overwrite_cassette_raise_error_disabled(get_client, tmpdir):
         )
 
     assert isinstance(response.error, CannotOverwriteExistingCassetteException)
+
+
+@pytest.mark.gen_test
+@vcr.use_cassette
+def test_tornado_with_decorator_use_cassette(get_client):
+    response = yield get_client().fetch(
+        http.HTTPRequest('http://www.google.com/', method='GET')
+    )
+    assert response.body == "not actually google"

tests/integration/test_tornado_with_decorator_use_cassette.yaml

@@ -0,0 +1,53 @@
+interactions:
+- request:
+    body: null
+    headers: {}
+    method: GET
+    uri: http://www.google.com/
+  response:
+    body: {string: !!python/unicode 'not actually google'}
+    headers:
+    - !!python/tuple
+      - Expires
+      - ['-1']
+    - !!python/tuple
+      - Connection
+      - [close]
+    - !!python/tuple
+      - P3p
+      - ['CP="This is not a P3P policy! See http://www.google.com/support/accounts/bin/answer.py?hl=en&answer=151657
+          for more info."']
+    - !!python/tuple
+      - Alternate-Protocol
+      - ['80:quic,p=0']
+    - !!python/tuple
+      - Accept-Ranges
+      - [none]
+    - !!python/tuple
+      - X-Xss-Protection
+      - [1; mode=block]
+    - !!python/tuple
+      - Vary
+      - [Accept-Encoding]
+    - !!python/tuple
+      - Date
+      - ['Thu, 30 Jul 2015 08:41:40 GMT']
+    - !!python/tuple
+      - Cache-Control
+      - ['private, max-age=0']
+    - !!python/tuple
+      - Content-Type
+      - [text/html; charset=ISO-8859-1]
+    - !!python/tuple
+      - Set-Cookie
+      - ['PREF=ID=1111111111111111:FF=0:TM=1438245700:LM=1438245700:V=1:S=GAzVO0ALebSpC_cJ;
+          expires=Sat, 29-Jul-2017 08:41:40 GMT; path=/; domain=.google.com', 'NID=69=Br7oRAwgmKoK__HC6FEnuxglTFDmFxqP6Md63lKhzW1w6WkDbp3U90CDxnUKvDP6wJH8yxY5Lk5ZnFf66Q1B0d4OsYoKgq0vjfBAYXuCIAWtOuGZEOsFXanXs7pt2Mjx;
+          expires=Fri, 29-Jan-2016 08:41:40 GMT; path=/; domain=.google.com; HttpOnly']
+    - !!python/tuple
+      - X-Frame-Options
+      - [SAMEORIGIN]
+    - !!python/tuple
+      - Server
+      - [gws]
+    status: {code: 200, message: OK}
+version: 1

tests/unit/test_cassettes.py

@@ -253,3 +253,37 @@ def test_func_path_generator():
     def function_name(cassette):
         assert cassette._path == os.path.join(os.path.dirname(__file__), 'function_name')
     function_name()
+
+
+def test_use_as_decorator_on_coroutine():
+    original_http_connetion = httplib.HTTPConnection
+    @Cassette.use(inject=True)
+    def test_function(cassette):
+        assert httplib.HTTPConnection.cassette is cassette
+        assert httplib.HTTPConnection is not original_http_connetion
+        value = yield 1
+        assert value == 1
+        assert httplib.HTTPConnection.cassette is cassette
+        assert httplib.HTTPConnection is not original_http_connetion
+        value = yield 2
+        assert value == 2
+    coroutine = test_function()
+    value = coroutine.next()
+    while True:
+        try:
+            value = coroutine.send(value)
+        except StopIteration:
+            break
+
+
+def test_use_as_decorator_on_generator():
+    original_http_connetion = httplib.HTTPConnection
+    @Cassette.use(inject=True)
+    def test_function(cassette):
+        assert httplib.HTTPConnection.cassette is cassette
+        assert httplib.HTTPConnection is not original_http_connetion
+        yield 1
+        assert httplib.HTTPConnection.cassette is cassette
+        assert httplib.HTTPConnection is not original_http_connetion
+        yield 2
+        assert list(test_function()) == [1, 2]

vcr/cassette.py

@@ -1,11 +1,8 @@
-"""The container for recorded requests and responses"""
-import functools
+import inspect
 import logging
 
-
 import wrapt
 
-# Internal imports
 from .compat import contextlib, collections
 from .errors import UnhandledHTTPRequestError
 from .matchers import requests_match, uri, method
@@ -50,14 +47,6 @@ class CassetteContextDecorator(object):
             # somewhere else.
             cassette._save()
 
-    @classmethod
-    def key_predicate(cls, key, value):
-        return key in cls._non_cassette_arguments
-
-    @classmethod
-    def _split_keys(cls, kwargs):
-        return partition_dict(cls.key_predicate, kwargs)
-
     def __enter__(self):
         # This assertion is here to prevent the dangerous behavior
         # that would result from forgetting about a __finish before
@@ -68,7 +57,10 @@ class CassetteContextDecorator(object):
         #     with context_decorator:
         #         pass
         assert self.__finish is None, "Cassette already open."
-        other_kwargs, cassette_kwargs = self._split_keys(self._args_getter())
+        other_kwargs, cassette_kwargs = partition_dict(
+            lambda key, _: key in self._non_cassette_arguments,
+            self._args_getter()
+        )
         if 'path_transformer' in other_kwargs:
             transformer = other_kwargs['path_transformer']
             cassette_kwargs['path'] = transformer(cassette_kwargs['path'])
@@ -84,27 +76,48 @@ class CassetteContextDecorator(object):
         # This awkward cloning thing is done to ensure that decorated
         # functions are reentrant. This is required for thread
         # safety and the correct operation of recursive functions.
-        args_getter = self._build_args_getter_for_decorator(
-            function, self._args_getter
-        )
-        clone = type(self)(self.cls, args_getter)
-        with clone as cassette:
-            if cassette.inject:
-                return function(cassette, *args, **kwargs)
-            else:
-                return function(*args, **kwargs)
+        args_getter = self._build_args_getter_for_decorator(function)
+        return type(self)(self.cls, args_getter)._execute_function(function, args, kwargs)
+
+    def _execute_function(self, function, args, kwargs):
+        if inspect.isgeneratorfunction(function):
+            handler = self._handle_coroutine
+        else:
+            handler = self._handle_function
+        return handler(function, args, kwargs)
+
+    def _handle_coroutine(self, function, args, kwargs):
+        with self as cassette:
+            coroutine = self.__handle_function(cassette, function, args, kwargs)
+            to_send = None
+            while True:
+                try:
+                    to_yield = coroutine.send(to_send)
+                except StopIteration:
+                    break
+                else:
+                    to_send = yield to_yield
+
+    def __handle_function(self, cassette, function, args, kwargs):
+        if cassette.inject:
+            return function(cassette, *args, **kwargs)
+        else:
+            return function(*args, **kwargs)
+
+    def _handle_function(self, function, args, kwargs):
+        with self as cassette:
+            self.__handle_function(cassette, function, args, kwargs)
 
     @staticmethod
     def get_function_name(function):
         return function.__name__
 
-    @classmethod
-    def _build_args_getter_for_decorator(cls, function, args_getter):
+    def _build_args_getter_for_decorator(self, function):
         def new_args_getter():
-            kwargs = args_getter()
+            kwargs = self._args_getter()
             if 'path' not in kwargs:
                 name_generator = (kwargs.get('func_path_generator') or
-                                  cls.get_function_name)
+                                  self.get_function_name)
                 path = name_generator(function)
                 kwargs['path'] = path
             return kwargs

vcr/config.py

@@ -23,7 +23,7 @@ class VCR(object):
             return path
         return ensure
 
-    def __init__(self, path_transformer=lambda x: x, before_record_request=None,
+    def __init__(self, path_transformer=None, before_record_request=None,
                  custom_patches=(), filter_query_parameters=(), ignore_hosts=(),
                  record_mode="once", ignore_localhost=False, filter_headers=(),
                  before_record_response=None, filter_post_data_parameters=(),
@@ -59,7 +59,7 @@ class VCR(object):
         self.ignore_hosts = ignore_hosts
         self.ignore_localhost = ignore_localhost
         self.inject_cassette = inject_cassette
-        self.path_transformer = path_transformer
+        self.path_transformer = path_transformer or self.ensure_suffix('.yaml')
         self.func_path_generator = func_path_generator
         self._custom_patches = tuple(custom_patches)
 
@@ -107,7 +107,7 @@ class VCR(object):
         matcher_names = kwargs.get('match_on', self.match_on)
         path_transformer = kwargs.get(
             'path_transformer',
-            self.path_transformer
+            self.path_transformer or self.ensure_suffix('.yaml')
         )
         func_path_generator = kwargs.get(
             'func_path_generator',