Add offline mode to skip tests that require an internet connection

Closes webrecorder#133.

pytest.ini

@@ -0,0 +1,3 @@
+[pytest]
+markers =
+    online: marks tests as requiring an internet connection

test/conftest.py

@@ -0,0 +1,16 @@
+import pytest
+
+
+def pytest_addoption(parser):
+    parser.addoption(
+        "--offline", action="store_true", help="Run tests in offline mode"
+    )
+
+@pytest.fixture
+def offline(request):
+    return request.config.getoption("--offline")
+
+@pytest.fixture(autouse=True)
+def skip_if_offline(request, offline):
+    if offline and request.node.get_closest_marker('online'):
+        pytest.skip('requires internet connection')

test/test_capture_http.py

@@ -5,7 +5,7 @@
 
 # must be imported before 'requests'
 from warcio.capture_http import capture_http
-from pytest import raises
+from pytest import raises, mark
 import requests
 
 import json
@@ -147,6 +147,7 @@ def nop_filter(request, response, recorder):
         data = request.content_stream().read().decode('utf-8')
         assert data == 'somedatatopost'
 
+    @mark.online()
     def test_post_chunked(self):
         warc_writer = BufferWARCWriter(gzip=False)
 
@@ -268,6 +269,7 @@ def test_warc_1_1(self):
 
         os.remove(full_path)
 
+    @mark.online()
     def test_remote(self):
         with capture_http(warc_version='1.1', gzip=True) as writer:
             requests.get('http://example.com/')

test/test_capture_http_proxy.py

@@ -7,7 +7,7 @@
 import requests
 from warcio.archiveiterator import ArchiveIterator
 
-from pytest import raises
+from pytest import raises, mark
 
 
 # ==================================================================
@@ -44,6 +44,7 @@ def run():
         thread.start()
         time.sleep(0.1)
 
+    @mark.online()
     def test_capture_http_proxy(self):
         with capture_http() as warc_writer:
             res = requests.get("http://example.com/test", proxies=self.proxies, verify=False)
@@ -63,6 +64,7 @@ def test_capture_http_proxy(self):
         with raises(StopIteration):
             assert next(ai)
 
+    @mark.online()
     def test_capture_https_proxy(self):
         with capture_http() as warc_writer:
             res = requests.get("https://example.com/test", proxies=self.proxies, verify=False)
@@ -109,6 +111,7 @@ def test_capture_https_proxy(self):
         with raises(StopIteration):
             assert next(ai)
 
+    @mark.online()
     def test_capture_https_proxy_same_session(self):
         sesh = requests.session()
         with capture_http() as warc_writer: