Make request.headers always a CaseInsensitiveDict.

Previously request.headers was a normal dict (albeit with the
request.add_header interface) which meant that some code paths would do
case-sensitive matching, for example remove_post_data_parameters which
tests for 'Content-Type'. This change allows all code paths to get the same
case-insensitive treatment.

Additionally request.headers becomes a property to enforce upgrading it to
a CaseInsensitiveDict even if assigned.

tests/integration/test_filter.py

@@ -17,11 +17,7 @@ def _request_with_auth(url, username, password):
 
 
 def _find_header(cassette, header):
-    for request in cassette.requests:
-        for k in request.headers:
-            if header.lower() == k.lower():
-                return True
-    return False
+    return any(header in request.headers for request in cassette.requests)
 
 
 def test_filter_basic_auth(tmpdir):

vcr/filters.py

@@ -1,19 +1,16 @@
 from six import BytesIO, text_type
 from six.moves.urllib.parse import urlparse, urlencode, urlunparse
-import copy
 import json
 
 from .compat import collections
 
 
 def remove_headers(request, headers_to_remove):
-    headers = copy.copy(request.headers)
-    headers_to_remove = [h.lower() for h in headers_to_remove]
-    keys = [k for k in headers if k.lower() in headers_to_remove]
-    if keys:
-        for k in keys:
-            headers.pop(k)
-        request.headers = headers
+    new_headers = request.headers.copy()
+    for k in headers_to_remove:
+        if k in new_headers:
+            del new_headers[k]
+    request.headers = new_headers
     return request
 
 

vcr/matchers.py

@@ -1,6 +1,6 @@
 import json
 from six.moves import urllib, xmlrpc_client
-from .util import CaseInsensitiveDict, read_body
+from .util import read_body
 import logging
 
 
@@ -66,9 +66,8 @@ def _identity(x):
 
 
 def _get_transformer(request):
-    headers = CaseInsensitiveDict(request.headers)
     for checker, transformer in _checker_transformer_pairs:
-        if checker(headers): return transformer
+        if checker(request.headers): return transformer
     else:
         return _identity
 

vcr/request.py

@@ -1,5 +1,6 @@
 from six import BytesIO, text_type
 from six.moves.urllib.parse import urlparse, parse_qsl
+from .util import CaseInsensitiveDict
 
 
 class Request(object):
@@ -32,9 +33,19 @@ class Request(object):
             self.body = body.read()
         else:
             self.body = body
-        self.headers = {}
-        for key in headers:
-            self.add_header(key, headers[key])
+        self.headers = CaseInsensitiveDict()
+        for key, value in headers.items():
+            self.add_header(key, value)
+
+    @property
+    def headers(self):
+        return self._headers
+
+    @headers.setter
+    def headers(self, value):
+        if not isinstance(value, CaseInsensitiveDict):
+            value = CaseInsensitiveDict(value)
+        self._headers = value
 
     @property
     def body(self):

vcr/stubs/tornado_stubs.py

@@ -15,7 +15,7 @@ def vcr_fetch_impl(cassette, real_fetch_impl):
 
     @functools.wraps(real_fetch_impl)
     def new_fetch_impl(self, request, callback):
-        headers = dict(request.headers)
+        headers = request.headers.copy()
         if request.user_agent:
             headers.setdefault('User-Agent', request.user_agent)