allow injection of persistence methods

tests/integration/test_persist_callbacks.py

@@ -0,0 +1,50 @@
+# -*- coding: utf-8 -*-
+'''Tests for cassettes with overriden persistence'''
+
+# External imports
+import os
+from six.moves.urllib.request import urlopen
+
+# Internal imports
+import vcr
+from vcr.persisters.filesystem import FilesystemPersister
+
+
+def test_overriding_save_cassette_with_callback(tmpdir, httpbin):
+    '''Ensure you can save a cassette using save_callback'''
+
+    def save_callback(cassette_path, data):
+        FilesystemPersister.write(cassette_path, data)
+
+    # Check to make sure directory doesnt exist
+    assert not os.path.exists(str(tmpdir.join('nonexistent')))
+
+    # Run VCR to create dir and cassette file using new save_cassette callback
+    with vcr.use_cassette(
+            str(tmpdir.join('nonexistent', 'cassette.yml')),
+            save_callback=save_callback
+    ):
+        urlopen(httpbin.url).read()
+
+    # Callback should have made the file and the directory
+    assert os.path.exists(str(tmpdir.join('nonexistent', 'cassette.yml')))
+
+
+def test_overriding_load_cassette_with_callback(tmpdir, httpbin):
+    '''
+    Ensure you can load a cassette using load_callback
+    '''
+    test_fixture = str(tmpdir.join('synopsis.json'))
+
+    def load_callback(cassette_path):
+        with open(cassette_path) as f:
+            cassette_content = f.read()
+        return cassette_content
+
+    with vcr.use_cassette(
+            test_fixture,
+            serializer='json',
+            load_callback=load_callback
+    ):
+        response = urlopen(httpbin.url).read()
+        assert b'difficult sometimes' in response