Fix PATH_PARAMETER_PATTERN for DRF default value pattern.

Django REST Framework will use `[^/.]+` as the default value pattern in
certain cases, e.g. `(?P<pk>[^/.]+)`, which doesn't work well with the
current regular expression in `PATH_PARAMETER_PATTERN`.

```
❯ git describe; git rev-parse HEAD
3.14.0-69-g0618fa88
0618fa88e1a8c2cf8a2aab29ef6de66b49e5f7ed

❯ git grep -n '\[^/.\]+'
rest_framework/routers.py:143:            self._default_value_pattern = '[^/.]+'
tests/test_routers.py:304:        expected = ['^notes/$', '^notes/(?P<pk>[^/.]+)/$']
tests/test_routers.py:319:        expected = ['^notes$', '^notes/(?P<pk>[^/.]+)$']
```

The fix inserts `(?:[^/]*?\[\^[^/]*/)?` before the final `[^/]*` in the
pattern. This allows matching a slash inside an inverted character set,
i.e. `[^...]`, treating it as part of the named group.

Author: ngnpope

openapi_core/contrib/django/requests.py

@@ -8,17 +8,19 @@
 
 from openapi_core.validation.request.datatypes import RequestParameters
 
-# https://docs.djangoproject.com/en/2.2/topics/http/urls/
+# https://docs.djangoproject.com/en/stable/topics/http/urls/
 #
 # Currently unsupported are :
 #   - nested arguments, e.g.: ^comments/(?:page-(?P<page_number>\d+)/)?$
 #   - unnamed regex groups, e.g.: ^articles/([0-9]{4})/$
 #   - multiple named parameters between a single pair of slashes
 #     e.g.: <page_slug>-<page_id>/edit/
 #
-# The regex matches everything, except a "/" until "<". Than only the name
+# The regex matches everything, except a "/" until "<". Then only the name
 # is exported, after which it matches ">" and everything until a "/".
-PATH_PARAMETER_PATTERN = r"(?:[^\/]*?)<(?:(?:.*?:))*?(\w+)>(?:[^\/]*)"
+# A check is made to ensure that "/" is not in an excluded character set such
+# as may be found with Django REST Framwork's default value pattern, "[^/.]+".
+PATH_PARAMETER_PATTERN = r"(?:[^/]*?)<(?:(?:.*?:))*?(\w+)>(?:(?:[^/]*?\[\^[^/]*/)?[^/]*)"
 
 
 class DjangoOpenAPIRequest:

tests/unit/contrib/django/test_django.py

@@ -43,6 +43,7 @@ def django_settings(self):
         settings.ROOT_URLCONF = (
             path("admin/", admin.site.urls),
             re_path("^test/test-regexp/$", lambda d: None),
+            re_path("^object/(?P<pk>[^/.]+)/action/$", lambda d: None),
         )
 
     @pytest.fixture
@@ -68,81 +69,53 @@ def test_no_resolver(self, request_factory):
 
         openapi_request = DjangoOpenAPIRequest(request)
 
-        path = {}
-        query = ImmutableMultiDict(
-            [
-                ("test1", "test2"),
-            ]
-        )
-        headers = Headers(
-            {
-                "Cookie": "",
-            }
-        )
-        cookies = {}
         assert openapi_request.parameters == RequestParameters(
-            path=path,
-            query=query,
-            header=headers,
-            cookie=cookies,
+            path={},
+            query=ImmutableMultiDict([("test1", "test2")]),
+            header=Headers({"Cookie": ""}),
+            cookie={},
         )
         assert openapi_request.method == request.method.lower()
         assert openapi_request.host_url == request._current_scheme_host
         assert openapi_request.path == request.path
+        assert openapi_request.path_pattern is None
         assert openapi_request.body == ""
         assert openapi_request.mimetype == request.content_type
 
     def test_simple(self, request_factory):
         from django.urls import resolve
 
         request = request_factory.get("/admin/")
-        request.resolver_match = resolve("/admin/")
+        request.resolver_match = resolve(request.path)
 
         openapi_request = DjangoOpenAPIRequest(request)
 
-        path = {}
-        query = {}
-        headers = Headers(
-            {
-                "Cookie": "",
-            }
-        )
-        cookies = {}
         assert openapi_request.parameters == RequestParameters(
-            path=path,
-            query=query,
-            header=headers,
-            cookie=cookies,
+            path={},
+            query={},
+            header=Headers({"Cookie": ""}),
+            cookie={},
         )
         assert openapi_request.method == request.method.lower()
         assert openapi_request.host_url == request._current_scheme_host
         assert openapi_request.path == request.path
+        assert openapi_request.path_pattern == request.path
         assert openapi_request.body == ""
         assert openapi_request.mimetype == request.content_type
 
     def test_url_rule(self, request_factory):
         from django.urls import resolve
 
         request = request_factory.get("/admin/auth/group/1/")
-        request.resolver_match = resolve("/admin/auth/group/1/")
+        request.resolver_match = resolve(request.path)
 
         openapi_request = DjangoOpenAPIRequest(request)
 
-        path = {
-            "object_id": "1",
-        }
-        query = {}
-        headers = Headers(
-            {
-                "Cookie": "",
-            }
-        )
-        cookies = {}
         assert openapi_request.parameters == RequestParameters(
-            path=path,
-            query=query,
-            header=headers,
-            cookie=cookies,
+            path={"object_id": "1"},
+            query={},
+            header=Headers({"Cookie": ""}),
+            cookie={},
         )
         assert openapi_request.method == request.method.lower()
         assert openapi_request.host_url == request._current_scheme_host
@@ -155,27 +128,41 @@ def test_url_regexp_pattern(self, request_factory):
         from django.urls import resolve
 
         request = request_factory.get("/test/test-regexp/")
-        request.resolver_match = resolve("/test/test-regexp/")
+        request.resolver_match = resolve(request.path)
 
         openapi_request = DjangoOpenAPIRequest(request)
 
-        path = {}
-        query = {}
-        headers = Headers(
-            {
-                "Cookie": "",
-            }
+        assert openapi_request.parameters == RequestParameters(
+            path={},
+            query={},
+            header=Headers({"Cookie": ""}),
+            cookie={},
         )
-        cookies = {}
+        assert openapi_request.method == request.method.lower()
+        assert openapi_request.host_url == request._current_scheme_host
+        assert openapi_request.path == request.path
+        assert openapi_request.path_pattern == request.path
+        assert openapi_request.body == ""
+        assert openapi_request.mimetype == request.content_type
+
+    def test_drf_default_value_pattern(self, request_factory):
+        from django.urls import resolve
+
+        request = request_factory.get("/object/123/action/")
+        request.resolver_match = resolve(request.path)
+
+        openapi_request = DjangoOpenAPIRequest(request)
+
         assert openapi_request.parameters == RequestParameters(
-            path=path,
-            query=query,
-            header=headers,
-            cookie=cookies,
+            path={"pk": "123"},
+            query={},
+            header=Headers({"Cookie": ""}),
+            cookie={},
         )
         assert openapi_request.method == request.method.lower()
         assert openapi_request.host_url == request._current_scheme_host
-        assert openapi_request.path == "/test/test-regexp/"
+        assert openapi_request.path == request.path
+        assert openapi_request.path_pattern == "/object/{pk}/action/"
         assert openapi_request.body == ""
         assert openapi_request.mimetype == request.content_type