Patch authority for backward compatibility

Author: rayluo

msal/authority.py

@@ -5,6 +5,11 @@
     from urlparse import urlparse
 import logging
 
+# Historically some customers patched this module-wide requests instance.
+# We keep it here for now. They will be removed in next major release.
+import requests
+import requests as _requests
+
 from .exceptions import MsalServiceError
 
 
@@ -33,6 +38,11 @@ class Authority(object):
     """
     _domains_without_user_realm_discovery = set([])
 
+    @property
+    def http_client(self):  # Obsolete. We will remove this in next major release.
+        # A workaround: if module-wide requests is patched, we honor it.
+        return self._http_client if requests is _requests else requests
+
     def __init__(self, authority_url, http_client, validate_authority=True):
         """Creates an authority instance, and also validates it.
 
@@ -42,7 +52,7 @@ def __init__(self, authority_url, http_client, validate_authority=True):
             This parameter only controls whether an instance discovery will be
             performed.
         """
-        self.http_client = http_client
+        self._http_client = http_client
         authority, self.instance, tenant = canonicalize(authority_url)
         parts = authority.path.split('/')
         is_b2c = any(self.instance.endswith("." + d) for d in WELL_KNOWN_B2C_HOSTS) or (

tests/test_authority_patch.py

@@ -0,0 +1,32 @@
+import unittest
+
+import msal
+from tests.http_client import MinimalHttpClient
+
+
+class DummyHttpClient(object):
+    def get(self, url, **kwargs):
+        raise RuntimeError("just for testing purpose")
+
+
+class TestAuthorityHonorsPatchedRequests(unittest.TestCase):
+    """This is only a workaround for an undocumented behavior."""
+    def test_authority_honors_a_patched_requests(self):
+        # First, we test that the original, unmodified authority is working
+        a = msal.authority.Authority(
+            "https://login.microsoftonline.com/common", MinimalHttpClient())
+        self.assertEqual(
+            a.authorization_endpoint,
+            'https://login.microsoftonline.com/common/oauth2/v2.0/authorize')
+
+        original = msal.authority.requests
+        try:
+            # Now we mimic a (discouraged) practice of patching authority.requests
+            msal.authority.requests = DummyHttpClient()
+            # msal.authority is expected to honor that patch.
+            with self.assertRaises(RuntimeError):
+                a = msal.authority.Authority(
+                    "https://login.microsoftonline.com/common", MinimalHttpClient())
+        finally:  # Tricky:
+            # Unpatch is necessary otherwise other test cases would be affected
+            msal.authority.requests = original