From 3ba7eaefd08f008846e9ffa74310104cafe66393 Mon Sep 17 00:00:00 2001
From: Edward Betts <edward@4angle.com>
Date: Thu, 14 May 2026 10:15:19 +0100
Subject: [PATCH] Show full Wikipedia 429 error message

---
 add_links/api.py |  2 +-
 test_api.py      | 30 ++++++++++++++++++++++++++++++
 web_view.py      | 17 ++++++++++++++---
 3 files changed, 45 insertions(+), 4 deletions(-)
 create mode 100644 test_api.py

diff --git a/add_links/api.py b/add_links/api.py
index 6f57def..0742fe2 100644
--- a/add_links/api.py
+++ b/add_links/api.py
@@ -98,7 +98,7 @@ def api_get(params: StrDict) -> StrDict:
         if webpage_error in r.text:
             raise MediawikiError(webpage_error)
         if r.status_code == 429:
-            raise MediawikiError("Wikipedia rate limit exceeded — wait a moment and try again.")
+            raise MediawikiError(r.text)
         raise MediawikiError(f"HTTP {r.status_code}: {r.text[:200]!r}")
     check_for_error(ret)
     return ret
diff --git a/test_api.py b/test_api.py
new file mode 100644
index 0000000..14968ca
--- /dev/null
+++ b/test_api.py
@@ -0,0 +1,30 @@
+import unittest
+from unittest.mock import Mock, patch
+
+from simplejson.scanner import JSONDecodeError
+
+from add_links import api
+
+
+class ApiGetTests(unittest.TestCase):
+    def test_429_error_preserves_full_message(self) -> None:
+        response = Mock()
+        response.status_code = 429
+        response.text = (
+            "Too many requests. If you are a tool operator, contact "
+            "noc@example.org for help."
+        )
+        response.json.side_effect = JSONDecodeError("bad json", "", 0)
+
+        session = Mock()
+        session.get.return_value = response
+
+        with patch("add_links.api._get_active_session", return_value=session):
+            with self.assertRaises(api.MediawikiError) as ctx:
+                api.api_get({"action": "query"})
+
+        self.assertEqual(str(ctx.exception), response.text)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/web_view.py b/web_view.py
index 7895c8d..6f7c9c5 100755
--- a/web_view.py
+++ b/web_view.py
@@ -37,6 +37,17 @@ class Hit(typing.TypedDict):
     timestamp: str
 
 
+def render_error(message: str) -> str:
+    """Render shared error page."""
+    return flask.render_template("error.html", message=message)
+
+
+def render_mediawiki_error(error: Exception, *, prefix: str | None = None) -> str:
+    """Render MediaWiki errors."""
+    message = f"{prefix}: {error}" if prefix else str(error)
+    return render_error(message)
+
+
 def load_examples() -> list[dict[str, str | int]]:
     """Load examples."""
     return [json.loads(line) for line in open("examples")]
@@ -203,7 +214,7 @@ def start_oauth() -> Response:
         fetch_response = oauth.fetch_request_token(request_token_url)
     except TokenRequestDenied as e:
         return flask.make_response(
-            flask.render_template("error.html", message=str(e)), 502
+            render_error(str(e)), 502
         )
 
     flask.session["owner_key"] = fetch_response.get("oauth_token")
@@ -325,7 +336,7 @@ def handle_post(url_title: str) -> Response:
         return flask.redirect(flask.url_for("start_oauth", next=next_url))
     except (mediawiki_api.APIError, api.MediawikiError) as e:
         return flask.make_response(
-            flask.render_template("error.html", message=f"Save failed: {e}"), 502
+            render_mediawiki_error(e, prefix="Save failed"), 502
         )
     flask.session["saves"] = flask.session.get("saves", 0) + 1
     saves_by_title: dict[str, int] = flask.session.get("saves_by_title", {})
@@ -357,7 +368,7 @@ def article_page(url_title: str) -> str | Response:
         _no_link_count, hits = search_no_link(from_title, redirect_to)
     except api.MediawikiError as e:
         return flask.make_response(
-            flask.render_template("error.html", message=str(e)), 502
+            render_mediawiki_error(e), 502
         )
 
     # Filter out candidates already processed this session