Automatically generate cassette names from function names. Add

`path_transformer` and `func_path_generator`. Closes #151.

vcr/config.py

@@ -1,23 +1,35 @@
 import collections
 import copy
 import functools
+import inspect
 import os
 
+import six
+
 from .cassette import Cassette
 from .serializers import yamlserializer, jsonserializer
+from .util import compose
 from . import matchers
 from . import filters
 
 
 class VCR(object):
 
-    def __init__(self, serializer='yaml', cassette_library_dir=None,
-                 record_mode="once", filter_headers=(), ignore_localhost=False,
-                 custom_patches=(), filter_query_parameters=(),
-                 filter_post_data_parameters=(), before_record_request=None,
-                 before_record_response=None, ignore_hosts=(),
+    @staticmethod
+    def ensure_suffix(suffix):
+        def ensure(path):
+            if not path.endswith(suffix):
+                return path + suffix
+            return path
+        return ensure
+
+    def __init__(self, path_transformer=lambda x: x, 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=(),
                  match_on=('method', 'scheme', 'host', 'port', 'path', 'query'),
-                 before_record=None, inject_cassette=False):
+                 before_record=None, inject_cassette=False, serializer='yaml',
+                 cassette_library_dir=None, func_path_generator=None):
         self.serializer = serializer
         self.match_on = match_on
         self.cassette_library_dir = cassette_library_dir
@@ -46,6 +58,8 @@ class VCR(object):
         self.ignore_hosts = ignore_hosts
         self.ignore_localhost = ignore_localhost
         self.inject_cassette = inject_cassette
+        self.path_transformer = path_transformer
+        self.func_path_generator = func_path_generator
         self._custom_patches = tuple(custom_patches)
 
     def _get_serializer(self, serializer_name):
@@ -69,27 +83,48 @@ class VCR(object):
             )
         return matchers
 
-    def use_cassette(self, path, with_current_defaults=False, **kwargs):
+    def use_cassette(self, path=None, **kwargs):
+        if path is not None and not isinstance(path, six.string_types):
+            function = path
+            # Assume this is an attempt to decorate a function
+            return self._use_cassette(**kwargs)(function)
+        return self._use_cassette(path=path, **kwargs)
+
+    def _use_cassette(self, with_current_defaults=False, **kwargs):
         if with_current_defaults:
-            path, config = self.get_path_and_merged_config(path, **kwargs)
-            return Cassette.use(path, **config)
+            config = self.get_merged_config(**kwargs)
+            return Cassette.use(**config)
         # This is made a function that evaluates every time a cassette
         # is made so that changes that are made to this VCR instance
         # that occur AFTER the `use_cassette` decorator is applied
         # still affect subsequent calls to the decorated function.
-        args_getter = functools.partial(self.get_path_and_merged_config,
-                                        path, **kwargs)
+        args_getter = functools.partial(self.get_merged_config, **kwargs)
         return Cassette.use_arg_getter(args_getter)
 
-    def get_path_and_merged_config(self, path, **kwargs):
+    def get_merged_config(self, **kwargs):
         serializer_name = kwargs.get('serializer', self.serializer)
         matcher_names = kwargs.get('match_on', self.match_on)
+        path_transformer = kwargs.get(
+            'path_transformer',
+            self.path_transformer
+        )
+        func_path_generator = kwargs.get(
+            'func_path_generator',
+            self.func_path_generator
+        )
         cassette_library_dir = kwargs.get(
             'cassette_library_dir',
             self.cassette_library_dir
         )
         if cassette_library_dir:
-            path = os.path.join(cassette_library_dir, path)
+            def add_cassette_library_dir(path):
+                if not path.startswith(cassette_library_dir):
+                    return os.path.join(cassette_library_dir, path)
+            path_transformer = compose(add_cassette_library_dir, path_transformer)
+        elif not func_path_generator:
+            # If we don't have a library dir, use the functions
+            # location to build a full path for cassettes.
+            func_path_generator = self._build_path_from_func_using_module
 
         merged_config = {
             'serializer': self._get_serializer(serializer_name),
@@ -102,9 +137,14 @@ class VCR(object):
             'custom_patches': self._custom_patches + kwargs.get(
                 'custom_patches', ()
             ),
-            'inject': kwargs.get('inject_cassette', self.inject_cassette)
+            'inject': kwargs.get('inject_cassette', self.inject_cassette),
+            'path_transformer': path_transformer,
+            'func_path_generator': func_path_generator
         }
-        return path, merged_config
+        path = kwargs.get('path')
+        if path:
+            merged_config['path'] = path
+        return merged_config
 
     def _build_before_record_response(self, options):
         before_record_response = options.get(
@@ -185,6 +225,11 @@ class VCR(object):
             return request
         return filter_ignored_hosts
 
+    @staticmethod
+    def _build_path_from_func_using_module(function):
+        return os.path.join(os.path.dirname(inspect.getfile(function)),
+                                            function.__name__)
+
     def register_serializer(self, name, serializer):
         self.serializers[name] = serializer