fix(client): log expected 401/404 fetch failures as concise warnings

dspace_rest_client/client.py

@@ -17,6 +17,7 @@
 import json
 import logging
 import os
+from urllib.parse import urlparse
 from uuid import UUID
 
 import requests
@@ -26,6 +27,9 @@
 
 __all__ = ['DSpaceClient']
 
+# cap on the response body echoed into an error log line
+_ERR_BODY_MAX = 500
+
 _logger = logging.getLogger("dspace.client")
 # A library must not configure the root logger - that is the consuming
 # application's job. Attach a NullHandler (once) so records are dropped unless
@@ -522,7 +526,20 @@ def fetch_resource(self, url, params=None):
             # record the failing response so callers can tell a 404 (the
             # resource is gone) from a transient 5xx before we drop the body
             self._last_err = r
-            _logger.error(f'Error encountered fetching resource: {r.text}')
+            # keep the query: on search endpoints it holds the only resource id
+            u = urlparse(r.url)
+            path = f'{u.path}?{u.query}' if u.query else u.path
+            if r.status_code == 401:
+                _logger.warning(
+                    f'DSpace returned 401 for [{path}] - authentication required '
+                    '(session expired or not logged in)')
+            elif r.status_code == 404:
+                _logger.warning(
+                    f'DSpace returned 404 for [{path}] - resource not found (deleted?)')
+            else:
+                _logger.error(
+                    f'Error encountered fetching resource: {r.status_code} for '
+                    f'[{path}]: {r.text[:_ERR_BODY_MAX]}')
             return None
         # ValueError / JSON handling moved to static method
         return parse_json(r)

tests/test_client_read.py

@@ -337,6 +337,50 @@ def test_404_returns_none_and_records_last_err(self):
             self.assertIsNone(c.fetch_resource(url))
             self.assertEqual(c.last_err.status_code, 404)
 
+    def test_401_logs_warning_with_path_not_body(self):
+        # expired session token or a client that never logged in
+        c = make_client()
+        url = f"{API}/core/items/{ITEM_UUID}/bundles"
+        with requests_mock.Mocker() as m:
+            m.get(url, status_code=401,
+                  json={"status": 401, "message": "Authentication is required"})
+            with self.assertLogs("dspace.client", level="WARNING") as logs:
+                self.assertIsNone(c.fetch_resource(url, params={"size": 10}))
+            self.assertEqual(c.last_err.status_code, 401)
+        self.assertEqual(logs.output, [
+            "WARNING:dspace.client:DSpace returned 401 for "
+            f"[/server/api/core/items/{ITEM_UUID}/bundles?size=10] - "
+            "authentication required (session expired or not logged in)"])
+
+    def test_404_logs_warning_with_path_and_query_not_body(self):
+        # on search endpoints the query carries the only id of the resource
+        c = make_client()
+        url = f"{API}/authz/resourcepolicies/search/resource"
+        with requests_mock.Mocker() as m:
+            m.get(url, status_code=404, json={"timestamp": "2026-01-01"})
+            with self.assertLogs("dspace.client", level="WARNING") as logs:
+                self.assertIsNone(c.fetch_resource(url, params={"uuid": ITEM_UUID}))
+        self.assertEqual(logs.output, [
+            "WARNING:dspace.client:DSpace returned 404 for "
+            f"[/server/api/authz/resourcepolicies/search/resource?uuid={ITEM_UUID}]"
+            " - resource not found (deleted?)"])
+
+    def test_other_error_logs_error_with_truncated_body(self):
+        c = make_client()
+        url = f"{API}/core/items/{ITEM_UUID}/bundles"
+        with requests_mock.Mocker() as m:
+            m.get(url, status_code=500, text="boom" + "x" * 5000)
+            with self.assertLogs("dspace.client", level="WARNING") as logs:
+                self.assertIsNone(c.fetch_resource(url, params={"size": 10}))
+            self.assertEqual(c.last_err.status_code, 500)
+        self.assertEqual(len(logs.records), 1)
+        rec = logs.records[0]
+        self.assertEqual(rec.levelname, "ERROR")
+        msg = rec.getMessage()
+        self.assertIn("500", msg)
+        self.assertIn(f"[/server/api/core/items/{ITEM_UUID}/bundles?size=10]", msg)
+        self.assertIn("boom", msg)
+        self.assertLess(len(msg), 1000)
 
 if __name__ == "__main__":
     unittest.main()