fix(django): Proper transaction names for i18n routes (#3104)

`pattern.pattern._route` for i18n'd Django routes is a proxy object rather than a string. This causes an exception in the resolver, leading to the transaction not getting a proper name but rather falling back to the default `Generic WSGI request`.

The string representation of the proxy object is the actual desired endpoint route, so let's use that.

sentry_sdk/integrations/django/transactions.py

@@ -74,7 +74,7 @@ def _simplify(self, pattern):
             and isinstance(pattern.pattern, RoutePattern)
         ):
             return self._new_style_group_matcher.sub(
-                lambda m: "{%s}" % m.group(2), pattern.pattern._route
+                lambda m: "{%s}" % m.group(2), str(pattern.pattern._route)
             )
 
         result = get_regex(pattern).pattern

tests/integrations/django/test_transactions.py

@@ -2,6 +2,7 @@
 
 import pytest
 import django
+from django.utils.translation import pgettext_lazy
 
 
 # django<2.0 has only `url` with regex based patterns.
@@ -116,3 +117,14 @@ def test_resolver_path_no_converter():
     resolver = RavenResolver()
     result = resolver.resolve("/api/v4/myproject", url_conf)
     assert result == "/api/v4/{project_id}"
+
+
+@pytest.mark.skipif(
+    django.VERSION < (2, 0),
+    reason="Django>=2.0 required for path patterns",
+)
+def test_resolver_path_with_i18n():
+    url_conf = (path(pgettext_lazy("url", "pgettext"), lambda x: ""),)
+    resolver = RavenResolver()
+    result = resolver.resolve("/pgettext", url_conf)
+    assert result == "/pgettext"