fix(procrastinate): invalidate cache after update; clarify defer wrap docs

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: snopoke

taskbadger/procrastinate.py

@@ -126,11 +126,14 @@ def _update_status(tb_id, status, exception=None):
             base = dict(current.data) if current.data else None
             data = DefaultMergeStrategy().merge(base, {"exception": str(exception)})
         if data is not None:
-            update_task_safe(tb_id, status=status, data=data)
+            updated = update_task_safe(tb_id, status=status, data=data)
         else:
-            update_task_safe(tb_id, status=status)
+            updated = update_task_safe(tb_id, status=status)
     else:
-        update_task_safe(tb_id, status=status)
+        updated = update_task_safe(tb_id, status=status)
+
+    if updated is not None:
+        _task_cache.set(tb_id, updated)
 
 
 class _Cache:
@@ -170,8 +173,9 @@ def _wrap_defer(task):
     """Wrap ``task.defer`` and ``task.defer_async`` so they create a TaskBadger
     task in PENDING state and inject its id into the job's task_kwargs.
 
-    The original defer methods are stashed on the task to keep the wrap
-    idempotent (a second call replaces nothing because the marker is set)."""
+    Not idempotent on its own — the caller (``_instrument_task``) gates this
+    via ``_INSTRUMENTED_ATTR`` so each task is wrapped at most once.
+    """
     original_defer = task.defer
     original_defer_async = task.defer_async
 

tests/test_procrastinate.py

@@ -81,6 +81,7 @@ def boom():
         mock.patch("taskbadger.procrastinate.get_task") as get,
     ):
         get.return_value = task_for_test(status=StatusEnum.PROCESSING, data={"x": 1})
+        update.return_value = task_for_test(status=StatusEnum.PROCESSING, data={"x": 1})
         with pytest.raises(ValueError, match="nope"):
             boom.func(**{TB_TASK_ID_KWARG: "tb-789"})