Extract is_api_request() and add unit tests

Extract `is_api_request()` into a shared helper function (instead of a
private method) and add unit tests.

Future commits will add code in multiple places that call the new shared
helper function.

But even with only one caller for the function there are still benefits
to extracting it and unit-testing it directly: when writing the tests I
noticed that it was returning `None` instead of `False` and added a
`bool()` call to fix this.

h/security/policy/combined.py

@@ -10,6 +10,7 @@
 from h.security.policy._identity_base import IdentityBasedPolicy
 from h.security.policy._remote_user import RemoteUserPolicy
 from h.security.policy.bearer_token import BearerTokenPolicy
+from h.security.policy.helpers import is_api_request
 
 
 @implementer(ISecurityPolicy)
@@ -69,7 +70,7 @@ def _call_sub_policies(self, method, request, *args, **kwargs):
         :return: The response from the correct sub-policy
         """
 
-        if not self._is_api_request(request):
+        if not is_api_request(request):
             # This is usually the cookie policy for UI things
             return getattr(self._ui_policy, method)(request, *args, **kwargs)
 
@@ -84,7 +85,3 @@ def _call_sub_policies(self, method, request, *args, **kwargs):
             )
 
         return result
-
-    @staticmethod
-    def _is_api_request(request):
-        return request.matched_route and request.matched_route.name.startswith("api.")

h/security/policy/helpers.py

@@ -0,0 +1,3 @@
+def is_api_request(request) -> bool:
+    """Return True if `request` is an API request."""
+    return bool(request.matched_route and request.matched_route.name.startswith("api."))

tests/unit/h/security/policy/helpers_test.py

@@ -0,0 +1,22 @@
+import pytest
+
+from h.security.policy.helpers import is_api_request
+
+
+@pytest.mark.parametrize(
+    "route_name,expected_result",
+    [
+        ("anything", False),
+        ("api.anything", True),
+    ],
+)
+def test_is_api_request(pyramid_request, route_name, expected_result):
+    pyramid_request.matched_route.name = route_name
+
+    assert is_api_request(pyramid_request) == expected_result
+
+
+def test_is_api_request_when_matched_route_is_None(pyramid_request):
+    pyramid_request.matched_route = None
+
+    assert is_api_request(pyramid_request) is False