random whitespace

Fix use_cassette when used as decorator does not return the wrapped function's return value

.gitignore

@@ -7,4 +7,5 @@ dist/
 *.egg-info/
 pytestdebug.log
 
-fixtures/
+fixtures/
+/docs/_build

.travis.yml

@@ -1,4 +1,5 @@
 language: python
+sudo: false
 before_install: openssl version
 env:
   global:
@@ -9,6 +10,7 @@ env:
     - WITH_LIB="requests2.3"
     - WITH_LIB="requests2.4"
     - WITH_LIB="requests2.5"
+    - WITH_LIB="requests2.6"
     - WITH_LIB="requests2.7"
     - WITH_LIB="requests1.x"
     - WITH_LIB="httplib2"
@@ -40,6 +42,7 @@ install:
 - if [ $WITH_LIB = "requests2.3" ] ; then pip install requests==2.3.0; fi
 - if [ $WITH_LIB = "requests2.4" ] ; then pip install requests==2.4.0; fi
 - if [ $WITH_LIB = "requests2.5" ] ; then pip install requests==2.5.0; fi
+- if [ $WITH_LIB = "requests2.6" ] ; then pip install requests==2.6.0; fi
 - if [ $WITH_LIB = "requests2.7" ] ; then pip install requests==2.7.0; fi
 - if [ $WITH_LIB = "httplib2" ] ; then pip install httplib2; fi
 - if [ $WITH_LIB = "boto" ] ; then pip install boto; fi

README.rst

@@ -1,16 +1,14 @@
+|Build Status| |Stories in Ready| |Gitter|
+
 VCR.py
 ======
 
-.. figure:: https://raw.github.com/kevin1024/vcrpy/master/vcr.png
+.. image:: https://raw.github.com/kevin1024/vcrpy/master/vcr.png
    :alt: vcr.py
 
-   vcr.py
-
 This is a Python version of `Ruby's VCR
 library <https://github.com/vcr/vcr>`__.
 
-|Build Status| |Stories in Ready|
-
 What it does
 ------------
 
@@ -575,6 +573,24 @@ If you set the loglevel to DEBUG, you will also get information about
 which matchers didn't match. This can help you with debugging custom
 matchers.
 
+Speed
+-----
+VCR.py runs about 10x faster when pyyaml can use the libyaml extensions. However, just installing ``libyaml`` (Mac) or ``libyaml-dev`` (Linux) is not enough, as pyyaml needs to be rebuild with the proper flag. Note that this flag is cached by pip, so clear the cache first. 
+
+Are you using libyaml already? This should work:
+
+.. code:: sh
+
+    python -c 'from yaml import CLoader'
+
+If not:
+
+.. code:: sh
+
+    pip uninstall pyyaml
+    pip --no-cache-dir install pyyaml
+
+
 Upgrade
 -------
 
@@ -609,7 +625,10 @@ new API in version 1.0.x
 
 Changelog
 ---------
--  1.7.3 [#188] ``additional_matchers`` kwarg on ``use_casstte``.
+-  1.7.4 [#217] Make use_cassette decorated functions actually return a
+   value (thanks @bcen). [#199] Fix path transfromation defaults.
+   Better headers dictionary management.
+-  1.7.3 [#188] ``additional_matchers`` kwarg on ``use_cassette``.
    [#191] Actually support passing multiple before_record_request
    functions (thanks @agriffis).
 -  1.7.2 [#186] Get effective_url in tornado (thanks @mvschaik), [#187]
@@ -758,3 +777,6 @@ more details
    :target: http://travis-ci.org/kevin1024/vcrpy
 .. |Stories in Ready| image:: https://badge.waffle.io/kevin1024/vcrpy.png?label=ready&title=Ready
    :target: https://waffle.io/kevin1024/vcrpy
+.. |Gitter| image:: https://badges.gitter.im/Join%20Chat.svg
+   :alt: Join the chat at https://gitter.im/kevin1024/vcrpy
+   :target: https://gitter.im/kevin1024/vcrpy?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge

docs/Makefile

@@ -0,0 +1,192 @@
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXOPTS    =
+SPHINXBUILD   = sphinx-build
+PAPER         =
+BUILDDIR      = _build
+
+# User-friendly check for sphinx-build
+ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
+$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/)
+endif
+
+# Internal variables.
+PAPEROPT_a4     = -D latex_paper_size=a4
+PAPEROPT_letter = -D latex_paper_size=letter
+ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+# the i18n builder cannot share the environment and doctrees with the others
+I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+
+.PHONY: help clean html dirhtml singlehtml pickle json htmlhelp qthelp devhelp epub latex latexpdf text man changes linkcheck doctest coverage gettext
+
+help:
+	@echo "Please use \`make <target>' where <target> is one of"
+	@echo "  html       to make standalone HTML files"
+	@echo "  dirhtml    to make HTML files named index.html in directories"
+	@echo "  singlehtml to make a single large HTML file"
+	@echo "  pickle     to make pickle files"
+	@echo "  json       to make JSON files"
+	@echo "  htmlhelp   to make HTML files and a HTML help project"
+	@echo "  qthelp     to make HTML files and a qthelp project"
+	@echo "  applehelp  to make an Apple Help Book"
+	@echo "  devhelp    to make HTML files and a Devhelp project"
+	@echo "  epub       to make an epub"
+	@echo "  latex      to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
+	@echo "  latexpdf   to make LaTeX files and run them through pdflatex"
+	@echo "  latexpdfja to make LaTeX files and run them through platex/dvipdfmx"
+	@echo "  text       to make text files"
+	@echo "  man        to make manual pages"
+	@echo "  texinfo    to make Texinfo files"
+	@echo "  info       to make Texinfo files and run them through makeinfo"
+	@echo "  gettext    to make PO message catalogs"
+	@echo "  changes    to make an overview of all changed/added/deprecated items"
+	@echo "  xml        to make Docutils-native XML files"
+	@echo "  pseudoxml  to make pseudoxml-XML files for display purposes"
+	@echo "  linkcheck  to check all external links for integrity"
+	@echo "  doctest    to run all doctests embedded in the documentation (if enabled)"
+	@echo "  coverage   to run coverage check of the documentation (if enabled)"
+
+clean:
+	rm -rf $(BUILDDIR)/*
+
+html:
+	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
+
+dirhtml:
+	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."
+
+singlehtml:
+	$(SPHINXBUILD) -b singlehtml $(ALLSPHINXOPTS) $(BUILDDIR)/singlehtml
+	@echo
+	@echo "Build finished. The HTML page is in $(BUILDDIR)/singlehtml."
+
+pickle:
+	$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
+	@echo
+	@echo "Build finished; now you can process the pickle files."
+
+json:
+	$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
+	@echo
+	@echo "Build finished; now you can process the JSON files."
+
+htmlhelp:
+	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
+	@echo
+	@echo "Build finished; now you can run HTML Help Workshop with the" \
+	      ".hhp project file in $(BUILDDIR)/htmlhelp."
+
+qthelp:
+	$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
+	@echo
+	@echo "Build finished; now you can run "qcollectiongenerator" with the" \
+	      ".qhcp project file in $(BUILDDIR)/qthelp, like this:"
+	@echo "# qcollectiongenerator $(BUILDDIR)/qthelp/vcrpy.qhcp"
+	@echo "To view the help file:"
+	@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/vcrpy.qhc"
+
+applehelp:
+	$(SPHINXBUILD) -b applehelp $(ALLSPHINXOPTS) $(BUILDDIR)/applehelp
+	@echo
+	@echo "Build finished. The help book is in $(BUILDDIR)/applehelp."
+	@echo "N.B. You won't be able to view it unless you put it in" \
+	      "~/Library/Documentation/Help or install it in your application" \
+	      "bundle."
+
+devhelp:
+	$(SPHINXBUILD) -b devhelp $(ALLSPHINXOPTS) $(BUILDDIR)/devhelp
+	@echo
+	@echo "Build finished."
+	@echo "To view the help file:"
+	@echo "# mkdir -p $$HOME/.local/share/devhelp/vcrpy"
+	@echo "# ln -s $(BUILDDIR)/devhelp $$HOME/.local/share/devhelp/vcrpy"
+	@echo "# devhelp"
+
+epub:
+	$(SPHINXBUILD) -b epub $(ALLSPHINXOPTS) $(BUILDDIR)/epub
+	@echo
+	@echo "Build finished. The epub file is in $(BUILDDIR)/epub."
+
+latex:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo
+	@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
+	@echo "Run \`make' in that directory to run these through (pdf)latex" \
+	      "(use \`make latexpdf' here to do that automatically)."
+
+latexpdf:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through pdflatex..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+latexpdfja:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through platex and dvipdfmx..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf-ja
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+text:
+	$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
+	@echo
+	@echo "Build finished. The text files are in $(BUILDDIR)/text."
+
+man:
+	$(SPHINXBUILD) -b man $(ALLSPHINXOPTS) $(BUILDDIR)/man
+	@echo
+	@echo "Build finished. The manual pages are in $(BUILDDIR)/man."
+
+texinfo:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo
+	@echo "Build finished. The Texinfo files are in $(BUILDDIR)/texinfo."
+	@echo "Run \`make' in that directory to run these through makeinfo" \
+	      "(use \`make info' here to do that automatically)."
+
+info:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo "Running Texinfo files through makeinfo..."
+	make -C $(BUILDDIR)/texinfo info
+	@echo "makeinfo finished; the Info files are in $(BUILDDIR)/texinfo."
+
+gettext:
+	$(SPHINXBUILD) -b gettext $(I18NSPHINXOPTS) $(BUILDDIR)/locale
+	@echo
+	@echo "Build finished. The message catalogs are in $(BUILDDIR)/locale."
+
+changes:
+	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
+	@echo
+	@echo "The overview file is in $(BUILDDIR)/changes."
+
+linkcheck:
+	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
+	@echo
+	@echo "Link check complete; look for any errors in the above output " \
+	      "or in $(BUILDDIR)/linkcheck/output.txt."
+
+doctest:
+	$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
+	@echo "Testing of doctests in the sources finished, look at the " \
+	      "results in $(BUILDDIR)/doctest/output.txt."
+
+coverage:
+	$(SPHINXBUILD) -b coverage $(ALLSPHINXOPTS) $(BUILDDIR)/coverage
+	@echo "Testing of coverage in the sources finished, look at the " \
+	      "results in $(BUILDDIR)/coverage/python.txt."
+
+xml:
+	$(SPHINXBUILD) -b xml $(ALLSPHINXOPTS) $(BUILDDIR)/xml
+	@echo
+	@echo "Build finished. The XML files are in $(BUILDDIR)/xml."
+
+pseudoxml:
+	$(SPHINXBUILD) -b pseudoxml $(ALLSPHINXOPTS) $(BUILDDIR)/pseudoxml
+	@echo
+	@echo "Build finished. The pseudo-XML files are in $(BUILDDIR)/pseudoxml."

docs/conf.py

@@ -0,0 +1,293 @@
+# -*- coding: utf-8 -*-
+#
+# vcrpy documentation build configuration file, created by
+# sphinx-quickstart on Sun Sep 13 11:18:00 2015.
+#
+# This file is execfile()d with the current directory set to its
+# containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+import sys
+import os
+import shlex
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#sys.path.insert(0, os.path.abspath('.'))
+
+# -- General configuration ------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    'sphinx.ext.autodoc',
+    'sphinx.ext.intersphinx',
+    'sphinx.ext.coverage',
+    'sphinx.ext.viewcode',
+]
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix(es) of source filenames.
+# You can specify multiple suffix as a list of string:
+# source_suffix = ['.rst', '.md']
+source_suffix = '.rst'
+
+# The encoding of source files.
+#source_encoding = 'utf-8-sig'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = u'vcrpy'
+copyright = u'2015, Kevin McCarthy'
+author = u'Kevin McCarthy'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+version = '1.7.3'
+# The full version, including alpha/beta/rc tags.
+release = '1.7.3'
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#
+# This is also used if you do content translation via gettext catalogs.
+# Usually you set "language" from the command line for these cases.
+language = None
+
+# There are two options for replacing |today|: either, you set today to some
+# non-false value, then it is used:
+#today = ''
+# Else, today_fmt is used as the format for a strftime call.
+#today_fmt = '%B %d, %Y'
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+exclude_patterns = ['_build']
+
+# The reST default role (used for this markup: `text`) to use for all
+# documents.
+#default_role = None
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+#add_function_parentheses = True
+
+# If true, the current module name will be prepended to all description
+# unit titles (such as .. function::).
+#add_module_names = True
+
+# If true, sectionauthor and moduleauthor directives will be shown in the
+# output. They are ignored by default.
+#show_authors = False
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# A list of ignored prefixes for module index sorting.
+#modindex_common_prefix = []
+
+# If true, keep warnings as "system message" paragraphs in the built documents.
+#keep_warnings = False
+
+# If true, `todo` and `todoList` produce output, else they produce nothing.
+todo_include_todos = False
+
+
+# -- Options for HTML output ----------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+html_theme = 'alabaster'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#html_theme_options = {}
+
+# Add any paths that contain custom themes here, relative to this directory.
+#html_theme_path = []
+
+# The name for this set of Sphinx documents.  If None, it defaults to
+# "<project> v<release> documentation".
+#html_title = None
+
+# A shorter title for the navigation bar.  Default is the same as html_title.
+#html_short_title = None
+
+# The name of an image file (relative to this directory) to place at the top
+# of the sidebar.
+#html_logo = None
+
+# The name of an image file (within the static path) to use as favicon of the
+# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
+# pixels large.
+#html_favicon = None
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+# Add any extra paths that contain custom files (such as robots.txt or
+# .htaccess) here, relative to this directory. These files are copied
+# directly to the root of the documentation.
+#html_extra_path = []
+
+# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
+# using the given strftime format.
+#html_last_updated_fmt = '%b %d, %Y'
+
+# If true, SmartyPants will be used to convert quotes and dashes to
+# typographically correct entities.
+#html_use_smartypants = True
+
+# Custom sidebar templates, maps document names to template names.
+#html_sidebars = {}
+
+# Additional templates that should be rendered to pages, maps page names to
+# template names.
+#html_additional_pages = {}
+
+# If false, no module index is generated.
+#html_domain_indices = True
+
+# If false, no index is generated.
+#html_use_index = True
+
+# If true, the index is split into individual pages for each letter.
+#html_split_index = False
+
+# If true, links to the reST sources are added to the pages.
+#html_show_sourcelink = True
+
+# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
+#html_show_sphinx = True
+
+# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
+#html_show_copyright = True
+
+# If true, an OpenSearch description file will be output, and all pages will
+# contain a <link> tag referring to it.  The value of this option must be the
+# base URL from which the finished HTML is served.
+#html_use_opensearch = ''
+
+# This is the file name suffix for HTML files (e.g. ".xhtml").
+#html_file_suffix = None
+
+# Language to be used for generating the HTML full-text search index.
+# Sphinx supports the following languages:
+#   'da', 'de', 'en', 'es', 'fi', 'fr', 'hu', 'it', 'ja'
+#   'nl', 'no', 'pt', 'ro', 'ru', 'sv', 'tr'
+#html_search_language = 'en'
+
+# A dictionary with options for the search language support, empty by default.
+# Now only 'ja' uses this config value
+#html_search_options = {'type': 'default'}
+
+# The name of a javascript file (relative to the configuration directory) that
+# implements a search results scorer. If empty, the default will be used.
+#html_search_scorer = 'scorer.js'
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'vcrpydoc'
+
+# -- Options for LaTeX output ---------------------------------------------
+
+latex_elements = {
+# The paper size ('letterpaper' or 'a4paper').
+#'papersize': 'letterpaper',
+
+# The font size ('10pt', '11pt' or '12pt').
+#'pointsize': '10pt',
+
+# Additional stuff for the LaTeX preamble.
+#'preamble': '',
+
+# Latex figure (float) alignment
+#'figure_align': 'htbp',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title,
+#  author, documentclass [howto, manual, or own class]).
+latex_documents = [
+  (master_doc, 'vcrpy.tex', u'vcrpy Documentation',
+   u'Kevin McCarthy', 'manual'),
+]
+
+# The name of an image file (relative to this directory) to place at the top of
+# the title page.
+#latex_logo = None
+
+# For "manual" documents, if this is true, then toplevel headings are parts,
+# not chapters.
+#latex_use_parts = False
+
+# If true, show page references after internal links.
+#latex_show_pagerefs = False
+
+# If true, show URL addresses after external links.
+#latex_show_urls = False
+
+# Documents to append as an appendix to all manuals.
+#latex_appendices = []
+
+# If false, no module index is generated.
+#latex_domain_indices = True
+
+
+# -- Options for manual page output ---------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    (master_doc, 'vcrpy', u'vcrpy Documentation',
+     [author], 1)
+]
+
+# If true, show URL addresses after external links.
+#man_show_urls = False
+
+
+# -- Options for Texinfo output -------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+  (master_doc, 'vcrpy', u'vcrpy Documentation',
+   author, 'vcrpy', 'One line description of project.',
+   'Miscellaneous'),
+]
+
+# Documents to append as an appendix to all manuals.
+#texinfo_appendices = []
+
+# If false, no module index is generated.
+#texinfo_domain_indices = True
+
+# How to display URL addresses: 'footnote', 'no', or 'inline'.
+#texinfo_show_urls = 'footnote'
+
+# If true, do not generate a @detailmenu in the "Top" node's menu.
+#texinfo_no_detailmenu = False
+
+
+# Example configuration for intersphinx: refer to the Python standard library.
+intersphinx_mapping = {'https://docs.python.org/': None}

docs/index.rst

@@ -0,0 +1,19 @@
+vcrpy
+=====
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+   vcr
+
+
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`
+

docs/vcr.rst

@@ -0,0 +1,6 @@
+:mod:`~vcr.config`
+=================
+
+.. automodule:: vcr.config
+   :members:
+   :special-members: __init__

setup.py

@@ -51,7 +51,7 @@ except Exception:
 
 setup(
     name='vcrpy',
-    version='1.7.3',
+    version='1.7.4',
     description=(
         "Automatically mock your HTTP interactions to simplify and "
         "speed up testing"

tests/integration/test_boto.py

@@ -1,5 +1,6 @@
 import pytest
 boto = pytest.importorskip("boto")
+
 import boto
 import boto.iam
 from boto.s3.connection import S3Connection
@@ -7,6 +8,7 @@ from boto.s3.key import Key
 from ConfigParser import DuplicateSectionError
 import vcr
 
+
 def test_boto_stubs(tmpdir):
     with vcr.use_cassette(str(tmpdir.join('boto-stubs.yml'))):
         # Perform the imports within the patched context so that
@@ -17,16 +19,18 @@ def test_boto_stubs(tmpdir):
         assert issubclass(CertValidatingHTTPSConnection, VCRCertValidatingHTTPSConnection)
         CertValidatingHTTPSConnection('hostname.does.not.matter')
 
+
 def test_boto_without_vcr():
     s3_conn = S3Connection()
-    s3_bucket = s3_conn.get_bucket('boto-demo-1394171994') # a bucket you can access
+    s3_bucket = s3_conn.get_bucket('boto-demo-1394171994')  # a bucket you can access
     k = Key(s3_bucket)
     k.key = 'test.txt'
     k.set_contents_from_string('hello world i am a string')
 
+
 def test_boto_medium_difficulty(tmpdir):
     s3_conn = S3Connection()
-    s3_bucket = s3_conn.get_bucket('boto-demo-1394171994') # a bucket you can access
+    s3_bucket = s3_conn.get_bucket('boto-demo-1394171994')  # a bucket you can access
     with vcr.use_cassette(str(tmpdir.join('boto-medium.yml'))) as cass:
         k = Key(s3_bucket)
         k.key = 'test.txt'
@@ -41,18 +45,19 @@ def test_boto_medium_difficulty(tmpdir):
 def test_boto_hardcore_mode(tmpdir):
     with vcr.use_cassette(str(tmpdir.join('boto-hardcore.yml'))) as cass:
         s3_conn = S3Connection()
-        s3_bucket = s3_conn.get_bucket('boto-demo-1394171994') # a bucket you can access
+        s3_bucket = s3_conn.get_bucket('boto-demo-1394171994')  # a bucket you can access
         k = Key(s3_bucket)
         k.key = 'test.txt'
         k.set_contents_from_string('hello world i am a string')
 
     with vcr.use_cassette(str(tmpdir.join('boto-hardcore.yml'))) as cass:
         s3_conn = S3Connection()
-        s3_bucket = s3_conn.get_bucket('boto-demo-1394171994') # a bucket you can access
+        s3_bucket = s3_conn.get_bucket('boto-demo-1394171994')  # a bucket you can access
         k = Key(s3_bucket)
         k.key = 'test.txt'
         k.set_contents_from_string('hello world i am a string')
 
+
 def test_boto_iam(tmpdir):
     try:
         boto.config.add_section('Boto')

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:
+    return any(header in request.headers for request in cassette.requests)
-        for k in request.headers:
-            if header.lower() == k.lower():
-                return True
-    return False
 
 
 def test_filter_basic_auth(tmpdir):

tests/unit/test_cassettes.py

@@ -10,6 +10,7 @@ from vcr.compat import mock, contextlib
 from vcr.cassette import Cassette
 from vcr.errors import UnhandledHTTPRequestError
 from vcr.patch import force_reset
+from vcr.matchers import path, method, query, host
 from vcr.stubs import VCRHTTPSConnection
 
 
@@ -245,6 +246,13 @@ def test_path_transformer_with_context_manager():
         assert cassette._path == 'a'
 
 
+def test_path_transformer_None():
+    with Cassette.use(
+        path='a', path_transformer=None,
+    ) as cassette:
+        assert cassette._path == 'a'
+
+
 def test_func_path_generator():
     def generator(function):
         return os.path.join(os.path.dirname(inspect.getfile(function)),
@@ -287,3 +295,18 @@ def test_use_as_decorator_on_generator():
         assert httplib.HTTPConnection is not original_http_connetion
         yield 2
     assert list(test_function()) == [1, 2]
+
+
+def test_similar_requests(tmpdir):
+    # WIP needs to be finished
+    @Cassette.use(inject=True, match_on=(path, query, host, method))
+    def test_function(cassette):
+        conn = httplib.HTTPConnection("www.python.org")
+        conn.request("GET", "/index.html?test=1")
+
+        conn = httplib.HTTPConnection("www.python.org")
+        conn.request("GET", "/index.html?test=0")
+
+        conn = httplib.HTTPConnection("www.cool.org")
+        conn.request("GET", "/index.html?test=0")
+        cassette.similar_requests()

tests/unit/test_filters.py

@@ -73,7 +73,7 @@ def test_remove_nonexistent_post_data_parameters():
 def test_remove_json_post_data_parameters():
     body = b'{"id": "secret", "foo": "bar", "baz": "qux"}'
     request = Request('POST', 'http://google.com', body, {})
-    request.add_header('Content-Type', 'application/json')
+    request.headers['Content-Type'] = 'application/json'
     remove_post_data_parameters(request, ['id'])
     request_body_json = json.loads(request.body.decode('utf-8'))
     expected_json = json.loads(b'{"foo": "bar", "baz": "qux"}'.decode('utf-8'))
@@ -83,7 +83,7 @@ def test_remove_json_post_data_parameters():
 def test_remove_all_json_post_data_parameters():
     body = b'{"id": "secret", "foo": "bar"}'
     request = Request('POST', 'http://google.com', body, {})
-    request.add_header('Content-Type', 'application/json')
+    request.headers['Content-Type'] = 'application/json'
     remove_post_data_parameters(request, ['id', 'foo'])
     assert request.body == b'{}'
 
@@ -91,6 +91,6 @@ def test_remove_all_json_post_data_parameters():
 def test_remove_nonexistent_json_post_data_parameters():
     body = b'{}'
     request = Request('POST', 'http://google.com', body, {})
-    request.add_header('Content-Type', 'application/json')
+    request.headers['Content-Type'] = 'application/json'
     remove_post_data_parameters(request, ['id'])
     assert request.body == b'{}'

tests/unit/test_request.py

@@ -1,6 +1,6 @@
 import pytest
 
-from vcr.request import Request
+from vcr.request import Request, HeadersDict
 
 
 def test_str():
@@ -12,11 +12,16 @@ def test_headers():
     headers = {'X-Header1': ['h1'], 'X-Header2': 'h2'}
     req = Request('GET', 'http://go.com/', '', headers)
     assert req.headers == {'X-Header1': 'h1', 'X-Header2': 'h2'}
-
+    req.headers['X-Header1'] = 'h11'
-    req.add_header('X-Header1', 'h11')
     assert req.headers == {'X-Header1': 'h11', 'X-Header2': 'h2'}
 
 
+def test_add_header_deprecated():
+    req = Request('GET', 'http://go.com/', '', {})
+    pytest.deprecated_call(req.add_header, 'foo', 'bar')
+    assert req.headers == {'foo': 'bar'}
+
+
 @pytest.mark.parametrize("uri, expected_port", [
     ('http://go.com/', 80),
     ('http://go.com:80/', 80),
@@ -36,3 +41,30 @@ def test_uri():
 
     req = Request('GET', 'http://go.com:80/', '', {})
     assert req.uri == 'http://go.com:80/'
+
+
+def test_HeadersDict():
+
+    # Simple test of CaseInsensitiveDict
+    h = HeadersDict()
+    assert h == {}
+    h['Content-Type'] = 'application/json'
+    assert h == {'Content-Type': 'application/json'}
+    assert h['content-type'] == 'application/json'
+    assert h['CONTENT-TYPE'] == 'application/json'
+
+    # Test feature of HeadersDict: devolve list to first element
+    h = HeadersDict()
+    assert h == {}
+    h['x'] = ['foo', 'bar']
+    assert h == {'x': 'foo'}
+
+    # Test feature of HeadersDict: preserve original key case
+    h = HeadersDict()
+    assert h == {}
+    h['Content-Type'] = 'application/json'
+    assert h == {'Content-Type': 'application/json'}
+    h['content-type'] = 'text/plain'
+    assert h == {'Content-Type': 'text/plain'}
+    h['CONtent-tyPE'] = 'whoa'
+    assert h == {'Content-Type': 'whoa'}

tests/unit/test_stubs.py

@@ -0,0 +1,7 @@
+from vcr.stubs import VCRHTTPSConnection
+
+class TestVCRConnection(object):
+    def test_setting_of_attributes_get_propogated_to_real_connection(self):
+        vcr_connection = VCRHTTPSConnection('www.examplehost.com')
+        vcr_connection.ssl_version = 'example_ssl_version'
+        assert vcr_connection.real_connection.ssl_version == 'example_ssl_version'

tests/unit/test_vcr.py

@@ -1,11 +1,13 @@
 import os
 
 import pytest
+from six.moves import http_client as httplib
 
 from vcr import VCR, use_cassette
 from vcr.compat import mock
 from vcr.request import Request
 from vcr.stubs import VCRHTTPSConnection
+from vcr.patch import _HTTPConnection, force_reset
 
 
 def test_vcr_use_cassette():
@@ -98,6 +100,43 @@ def test_vcr_before_record_response_iterable():
             assert mock_filter.call_count == 1
 
 
+def test_before_record_response_as_filter():
+    request = Request('GET', '/', '', {})
+    response = object()  # just can't be None
+
+    # Prevent actually saving the cassette
+    with mock.patch('vcr.cassette.save_cassette'):
+
+        filter_all = mock.Mock(return_value=None)
+        vcr = VCR(before_record_response=filter_all)
+        with vcr.use_cassette('test') as cassette:
+            cassette.append(request, response)
+            assert cassette.data == []e
+            assert not cassette.dirty
+
+
+def test_vcr_path_transformer():
+    # Regression test for #199
+
+    # Prevent actually saving the cassette
+    with mock.patch('vcr.cassette.save_cassette'):
+
+        # Baseline: path should be unchanged
+        vcr = VCR()
+        with vcr.use_cassette('test') as cassette:
+            assert cassette._path == 'test'
+
+        # Regression test: path_transformer=None should do the same.
+        vcr = VCR(path_transformer=None)
+        with vcr.use_cassette('test') as cassette:
+            assert cassette._path == 'test'
+
+        # and it should still work with cassette_library_dir
+        vcr = VCR(cassette_library_dir='/foo')
+        with vcr.use_cassette('test') as cassette:
+            assert cassette._path == '/foo/test'
+
+
 @pytest.fixture
 def random_fixture():
     return 1
@@ -243,6 +282,7 @@ def test_path_transformer():
 
 def test_cassette_name_generator_defaults_to_using_module_function_defined_in():
     vcr = VCR(inject_cassette=True)
+
     @vcr.use_cassette
     def function_name(cassette):
         assert cassette._path == os.path.join(os.path.dirname(__file__),
@@ -274,3 +314,40 @@ def test_additional_matchers():
 
     function_defaults()
     function_additional()
+
+
+def test_decoration_should_respect_function_return_value():
+    vcr = VCR()
+    ret = 'a-return-value'
+
+    @vcr.use_cassette
+    def function_with_return():
+        return ret
+
+    assert ret == function_with_return()
+
+
+class TestVCRClass(VCR().test_case()):
+
+    def no_decoration(self):
+        assert httplib.HTTPConnection == _HTTPConnection
+        self.test_dynamically_added()
+        assert httplib.HTTPConnection == _HTTPConnection
+
+    def test_one(self):
+        with force_reset():
+            self.no_decoration()
+        with force_reset():
+            self.test_two()
+        assert httplib.HTTPConnection != _HTTPConnection
+
+    def test_two(self):
+        assert httplib.HTTPConnection != _HTTPConnection
+
+
+def test_dynamically_added(self):
+    assert httplib.HTTPConnection != _HTTPConnection
+
+
+TestVCRClass.test_dynamically_added = test_dynamically_added
+del test_dynamically_added

vcr/cassette.py

@@ -1,6 +1,7 @@
-import sys
 import inspect
 import logging
+import operator
+import sys
 
 import wrapt
 
@@ -75,7 +76,7 @@ class CassetteContextDecorator(object):
             lambda key, _: key in self._non_cassette_arguments,
             self._args_getter()
         )
-        if 'path_transformer' in other_kwargs:
+        if other_kwargs.get('path_transformer'):
             transformer = other_kwargs['path_transformer']
             cassette_kwargs['path'] = transformer(cassette_kwargs['path'])
         self.__finish = self._patch_generator(self.cls.load(**cassette_kwargs))
@@ -127,7 +128,7 @@ class CassetteContextDecorator(object):
 
     def _handle_function(self, function, args, kwargs):
         with self as cassette:
-            self.__handle_function(cassette, function, args, kwargs)
+            return self.__handle_function(cassette, function, args, kwargs)
 
     @staticmethod
     def get_function_name(function):
@@ -145,9 +146,33 @@ class CassetteContextDecorator(object):
         return new_args_getter
 
 
+class SimilarityScorer(object):
+
+    def __init__(self, matchers, request, ascending=False):
+        self._matchers = matchers
+        self._request = request
+        self._ascending = False
+
+    def score(self, candidate, play_count):
+        value = 1
+        total = 0
+        if play_count < 1:
+            total += value
+        if self._ascending:
+            value *= 2
+        for matcher in self._matchers[::-1]:
+            if matcher(self._request, candidate):
+                total += value
+            if self._ascending:
+                value *= 2
+        return total
+
+
 class Cassette(object):
     """A container for recorded requests and responses"""
 
+    max_playcount = 1
+
     @classmethod
     def load(cls, **kwargs):
         """Instantiate and load the cassette stored at the specified path."""
@@ -165,14 +190,15 @@ class Cassette(object):
 
     def __init__(self, path, serializer=yamlserializer, record_mode='once',
                  match_on=(uri, method), before_record_request=None,
-                 before_record_response=None, custom_patches=(),
+                 before_record_response=None, custom_patches=(), inject=False,
-                 inject=False):
+                 similarity_scorer_factory=None):
 
         self._path = path
         self._serializer = serializer
         self._match_on = match_on
         self._before_record_request = before_record_request or (lambda x: x)
         self._before_record_response = before_record_response or (lambda x: x)
+        self._similarity_scorer_factory = similarity_scorer_factory or SimilarityScorer
         self.inject = inject
         self.record_mode = record_mode
         self.custom_patches = custom_patches
@@ -211,6 +237,8 @@ class Cassette(object):
         if not request:
             return
         response = self._before_record_response(response)
+        if response is None:
+            return
         self.data.append((request, response))
         self.dirty = True
 
@@ -227,6 +255,20 @@ class Cassette(object):
             if requests_match(request, stored_request, self._match_on):
                 yield index, response
 
+    def failing_matchers(self, a, b):
+        return [matcher for matcher in self._match_on if not matcher(a, b)]
+
+    def similar_requests(self, request):
+        scorer = self._similarity_scorer_factory(self._match_on, request).score
+        scored_requests = [
+            (
+                stored_request,
+                scorer(stored_request, self.play_counts[index])
+            )
+            for index, (stored_request, response) in enumerate(self.data)
+        ]
+        return sorted(scored_requests, key=operator.itemgetter(1), reverse=True)
+
     def can_play_response_for(self, request):
         request = self._before_record_request(request)
         return request and request in self and \
@@ -239,7 +281,7 @@ class Cassette(object):
         hasn't been played back before, and mark it as played
         """
         for index, response in self._responses(request):
-            if self.play_counts[index] == 0:
+            if self.play_counts[index] < self.max_playcount:
                 self.play_counts[index] += 1
                 return response
         # The cassette doesn't contain the request asked for.

vcr/config.py

@@ -2,19 +2,25 @@ import copy
 import functools
 import inspect
 import os
+import types
 
 import six
 
 from .compat import collections
 from .cassette import Cassette
 from .serializers import yamlserializer, jsonserializer
-from .util import compose
+from .util import compose, auto_decorate
 from . import matchers
 from . import filters
 
 
 class VCR(object):
 
+    @staticmethod
+    def is_test_method(method_name, function):
+        return method_name.startswith('test') and \
+            isinstance(function, types.FunctionType)
+
     @staticmethod
     def ensure_suffix(suffix):
         def ensure(path):
@@ -23,7 +29,7 @@ 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=(),
@@ -108,7 +114,7 @@ class VCR(object):
         matcher_names = kwargs.get('match_on', self.match_on)
         path_transformer = kwargs.get(
             'path_transformer',
-            self.path_transformer or self.ensure_suffix('.yaml')
+            self.path_transformer
         )
         func_path_generator = kwargs.get(
             'func_path_generator',
@@ -202,7 +208,7 @@ class VCR(object):
         if filter_query_parameters:
             filter_functions.append(functools.partial(
                 filters.remove_query_parameters,
-                query_parameters_to_remove=filter_query_parameters
+               query_parameters_to_remove=filter_query_parameters
             ))
         if filter_post_data_parameters:
             filter_functions.append(
@@ -250,3 +256,7 @@ class VCR(object):
 
     def register_matcher(self, name, matcher):
         self.matchers[name] = matcher
+
+    def test_case(self, predicate=None):
+        predicate = predicate or self.is_test_method
+        return six.with_metaclass(auto_decorate(self.use_cassette, predicate))

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)
+    new_headers = request.headers.copy()
-    headers_to_remove = [h.lower() for h in headers_to_remove]
+    for k in headers_to_remove:
-    keys = [k for k in headers if k.lower() in headers_to_remove]
+        if k in new_headers:
-    if keys:
+            del new_headers[k]
-        for k in keys:
+    request.headers = new_headers
-            headers.pop(k)
-        request.headers = headers
     return request
 
 
@@ -30,8 +27,7 @@ def remove_query_parameters(request, query_parameters_to_remove):
 
 def remove_post_data_parameters(request, post_data_parameters_to_remove):
     if request.method == 'POST' and not isinstance(request.body, BytesIO):
-        if ('Content-Type' in request.headers and
+        if request.headers.get('Content-Type') == 'application/json':
-                request.headers['Content-Type'] == 'application/json'):
             json_data = json.loads(request.body.decode('utf-8'))
             for k in list(json_data.keys()):
                 if k in post_data_parameters_to_remove:

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

@@ -1,27 +1,12 @@
+import warnings
 from six import BytesIO, text_type
 from six.moves.urllib.parse import urlparse, parse_qsl
+from .util import CaseInsensitiveDict
 
 
 class Request(object):
     """
-    VCR's  representation of a request.
+    VCR's representation of a request.
-
-    There is a weird quirk in HTTP.  You can send the same header twice.  For
-    this reason, headers are represented by a dict, with lists as the values.
-    However, it appears that HTTPlib is completely incapable of sending the
-    same header twice.  This puts me in a weird position: I want to be able to
-    accurately represent HTTP headers in cassettes, but I don't want the extra
-    step of always having to do [0] in the general case, i.e.
-    request.headers['key'][0]
-
-    In addition, some servers sometimes send the same header more than once,
-    and httplib *can* deal with this situation.
-
-    Futhermore, I wanted to keep the request and response cassette format as
-    similar as possible.
-
-    For this reason, in cassettes I keep a dict with lists as keys, but once
-    deserialized into VCR, I keep them as plain, naked dicts.
     """
 
     def __init__(self, method, uri, body, headers):
@@ -32,9 +17,17 @@ class Request(object):
             self.body = body.read()
         else:
             self.body = body
-        self.headers = {}
+        self.headers = headers
-        for key in headers:
+
-            self.add_header(key, headers[key])
+    @property
+    def headers(self):
+        return self._headers
+
+    @headers.setter
+    def headers(self, value):
+        if not isinstance(value, HeadersDict):
+            value = HeadersDict(value)
+        self._headers = value
 
     @property
     def body(self):
@@ -47,11 +40,10 @@ class Request(object):
         self._body = value
 
     def add_header(self, key, value):
-        # see class docstring for an explanation
+        warnings.warn("Request.add_header is deprecated. "
-        if isinstance(value, (tuple, list)):
+                      "Please assign to request.headers instead.",
-            self.headers[key] = value[0]
+                      DeprecationWarning)
-        else:
+        self.headers[key] = value
-            self.headers[key] = value
 
     @property
     def scheme(self):
@@ -105,3 +97,35 @@ class Request(object):
     @classmethod
     def _from_dict(cls, dct):
         return Request(**dct)
+
+
+class HeadersDict(CaseInsensitiveDict):
+    """
+    There is a weird quirk in HTTP.  You can send the same header twice.  For
+    this reason, headers are represented by a dict, with lists as the values.
+    However, it appears that HTTPlib is completely incapable of sending the
+    same header twice.  This puts me in a weird position: I want to be able to
+    accurately represent HTTP headers in cassettes, but I don't want the extra
+    step of always having to do [0] in the general case, i.e.
+    request.headers['key'][0]
+
+    In addition, some servers sometimes send the same header more than once,
+    and httplib *can* deal with this situation.
+
+    Futhermore, I wanted to keep the request and response cassette format as
+    similar as possible.
+
+    For this reason, in cassettes I keep a dict with lists as keys, but once
+    deserialized into VCR, I keep them as plain, naked dicts.
+    """
+
+    def __setitem__(self, key, value):
+        if isinstance(value, (tuple, list)):
+            value = value[0]
+
+        # Preserve the case from the first time this key was set.
+        old = self._store.get(key.lower())
+        if old:
+            key = old[0]
+
+        super(HeadersDict, self).__setitem__(key, value)

vcr/stubs/__init__.py

@@ -9,7 +9,6 @@ import six
 from six.moves.http_client import (
     HTTPConnection,
     HTTPSConnection,
-    HTTPMessage,
     HTTPResponse,
 )
 from six import BytesIO
@@ -188,8 +187,7 @@ class VCRConnection(object):
         log.debug('Got {0}'.format(self._vcr_request))
 
     def putheader(self, header, *values):
-        for value in values:
+        self._vcr_request.headers[header] = values
-            self._vcr_request.add_header(header, value)
 
     def send(self, data):
         '''
@@ -229,12 +227,26 @@ class VCRConnection(object):
             if self.cassette.write_protected and self.cassette.filter_request(
                 self._vcr_request
             ):
+                most_similar_request = None
+                failing_matchers = None
+                most_similar_request_info = None
+                try:
+                    most_similar_request_info = self.cassette.similar_requests(self._vcr_request)
+                    most_similar_request = most_similar_request_info[0][0]
+                    failing_matchers = self.cassette.failing_matchers(
+                        self._vcr_request, most_similar_request
+                    )
+                except Exception as err:
+                    print "XXXX {0}".format(err)
+                    import ipdb; ipdb.set_trace()
                 raise CannotOverwriteExistingCassetteException(
                     "No match for the request (%r) was found. "
                     "Can't overwrite existing cassette (%r) in "
-                    "your current record mode (%r)."
+                    "your current record mode (%r). Most similar request was (%r). "
+                    "It differed from the request according to (%r). \n\n\n(%r)"
                     % (self._vcr_request, self.cassette._path,
-                       self.cassette.record_mode)
+                       self.cassette.record_mode, most_similar_request,
+                       failing_matchers, most_similar_request_info)
                 )
 
             # Otherwise, we should send the request, then get the response
@@ -307,7 +319,7 @@ class VCRConnection(object):
 
     def __init__(self, *args, **kwargs):
         if six.PY3:
-            kwargs.pop('strict', None) # apparently this is gone in py3
+            kwargs.pop('strict', None)  # apparently this is gone in py3
 
         # need to temporarily reset here because the real connection
         # inherits from the thing that we are mocking out.  Take out
@@ -316,6 +328,27 @@ class VCRConnection(object):
         with force_reset():
             self.real_connection = self._baseclass(*args, **kwargs)
 
+    def __setattr__(self, name, value):
+        """
+        We need to define this because any attributes that are set on the
+        VCRConnection need to be propogated to the real connection.
+
+        For example, urllib3 will set certain attributes on the connection,
+        such as 'ssl_version'. These attributes need to get set on the real
+        connection to have the correct and expected behavior.
+
+        TODO: Separately setting the attribute on the two instances is not
+        ideal. We should switch to a proxying implementation.
+        """
+        try:
+            setattr(self.real_connection, name, value)
+        except AttributeError:
+             # raised if real_connection has not been set yet, such as when
+             # we're setting the real_connection itself for the first time
+            pass
+
+        super(VCRConnection, self).__setattr__(name, value)
+
 
 class VCRHTTPConnection(VCRConnection):
     '''A Mocked class for HTTP requests'''

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)
 

vcr/util.py

@@ -1,4 +1,6 @@
 import collections
+import types
+
 
 # Shamelessly stolen from https://github.com/kennethreitz/requests/blob/master/requests/structures.py
 class CaseInsensitiveDict(collections.MutableMapping):
@@ -81,8 +83,9 @@ def partition_dict(predicate, dictionary):
 def compose(*functions):
     def composed(incoming):
         res = incoming
-        for function in functions[::-1]:
+        for function in reversed(functions):
-            res = function(res)
+            if function:
+                res = function(res)
         return res
     return composed
 
@@ -90,3 +93,30 @@ def read_body(request):
     if hasattr(request.body, 'read'):
         return request.body.read()
     return request.body
+
+
+def auto_decorate(
+    decorator,
+    predicate=lambda name, value: isinstance(value, types.FunctionType)
+):
+    def maybe_decorate(attribute, value):
+        if predicate(attribute, value):
+            value = decorator(value)
+        return value
+
+    class DecorateAll(type):
+
+        def __setattr__(cls, attribute, value):
+            return super(DecorateAll, cls).__setattr__(
+                attribute, maybe_decorate(attribute, value)
+            )
+
+        def __new__(cls, name, bases, attributes_dict):
+            new_attributes_dict = dict(
+                (attribute, maybe_decorate(attribute, value))
+                for attribute, value in attributes_dict.items()
+            )
+            return super(DecorateAll, cls).__new__(
+                cls, name, bases, new_attributes_dict
+            )
+    return DecorateAll