Enable brotli decompression if it is available

tests/integration/test_filter.py

@@ -4,6 +4,7 @@
 from urllib.parse import urlencode
 from urllib.error import HTTPError
 import vcr
+from vcr.filters import brotli
 import json
 from assertions import assert_cassette_has_one_response, assert_is_json
 
@@ -118,6 +119,22 @@ def test_decompress_deflate(tmpdir, httpbin):
     assert_is_json(decoded_response)
 
 
+def test_decompress_brotli(tmpdir, httpbin):
+    if brotli is None:
+        # XXX: this is never true, because brotlipy is installed with "httpbin"
+        pytest.skip('Brotli is not installed')
+
+    url = httpbin.url + "/brotli"
+    request = Request(url, headers={"Accept-Encoding": ["gzip, deflate, br"]})
+    cass_file = str(tmpdir.join("brotli_response.yaml"))
+    with vcr.use_cassette(cass_file, decode_compressed_response=True):
+        urlopen(request)
+    with vcr.use_cassette(cass_file) as cass:
+        decoded_response = urlopen(url).read()
+        assert_cassette_has_one_response(cass)
+    assert_is_json(decoded_response)
+
+
 def test_decompress_regular(tmpdir, httpbin):
     """Test that it doesn't try to decompress content that isn't compressed"""
     url = httpbin.url + "/get"

tox.ini

@@ -3,8 +3,8 @@ skip_missing_interpreters=true
 envlist =
   cov-clean,
   lint,
-  {py37,py38,py39,py310}-{requests,httplib2,urllib3,tornado4,boto3,aiohttp,httpx},
-  {pypy3}-{requests,httplib2,urllib3,tornado4,boto3},
+  {py37,py38,py39,py310}-{requests,httplib2,urllib3,tornado4,boto3,aiohttp,httpx,brotli,brotlipy,brotlicffi},
+  {pypy3}-{requests,httplib2,urllib3,tornado4,boto3,brotli,brotlipy,brotlicffi},
   {py310}-httpx019,
   cov-report
 
@@ -93,6 +93,9 @@ deps =
     # httpx==0.19 is the latest version that supports allow_redirects, newer versions use follow_redirects
     httpx019: httpx==0.19
     {py37,py38,py39,py310}-{httpx}: pytest-asyncio
+    brotli: brotli
+    brotlipy: brotlipy
+    brotlicffi: brotlicffi
 depends =
   lint,{py37,py38,py39,py310,pypy3}-{requests,httplib2,urllib3,tornado4,boto3},{py37,py38,py39,py310}-{aiohttp},{py37,py38,py39,py310}-{httpx}: cov-clean
   cov-report: lint,{py37,py38,py39,py310,pypy3}-{requests,httplib2,urllib3,tornado4,boto3},{py37,py38,py39,py310}-{aiohttp}

vcr/filters.py

@@ -6,6 +6,20 @@
 
 from .util import CaseInsensitiveDict
 
+try:
+    # This supports both brotli & brotlipy packages
+    import brotli
+except ImportError:
+    try:
+        import brotlicffi as brotli
+    except ImportError:
+        brotli = None
+
+
+AVAILABLE_DECOMPRESSORS = {'gzip', 'deflate'}
+if brotli is not None:
+    AVAILABLE_DECOMPRESSORS.add('br')
+
 
 def replace_headers(request, replacements):
     """Replace headers in request according to replacements.
@@ -136,30 +150,33 @@ def remove_post_data_parameters(request, post_data_parameters_to_remove):
 
 def decode_response(response):
     """
-    If the response is compressed with gzip or deflate:
+    If the response is compressed with any supported compression (gzip,
+    deflate, br if available):
       1. decompress the response body
       2. delete the content-encoding header
       3. update content-length header to decompressed length
     """
 
-    def is_compressed(headers):
+    def is_decompressable(headers):
         encoding = headers.get("content-encoding", [])
-        return encoding and encoding[0] in ("gzip", "deflate")
+        return encoding and encoding[0] in AVAILABLE_DECOMPRESSORS
 
     def decompress_body(body, encoding):
         """Returns decompressed body according to encoding using zlib.
         to (de-)compress gzip format, use wbits = zlib.MAX_WBITS | 16
         """
         if encoding == "gzip":
             return zlib.decompress(body, zlib.MAX_WBITS | 16)
-        else:  # encoding == 'deflate'
+        elif encoding == "deflate":
             return zlib.decompress(body)
+        else:  # encoding == 'br'
+            return brotli.decompress(body)
 
     # Deepcopy here in case `headers` contain objects that could
     # be mutated by a shallow copy and corrupt the real response.
     response = copy.deepcopy(response)
     headers = CaseInsensitiveDict(response["headers"])
-    if is_compressed(headers):
+    if is_decompressable(headers):
         encoding = headers["content-encoding"][0]
         headers["content-encoding"].remove(encoding)
         if not headers["content-encoding"]: