fix(logger): copy thread-local keys in thread_safe_remove_keys

aws_lambda_powertools/logging/formatter.py

@@ -490,7 +490,8 @@ def set_context_keys(**kwargs: dict[str, Any]) -> None:
 
 def remove_context_keys(keys: Iterable[str]) -> None:
     context = _get_context()
-    context_values = context.get()
+    # Copy instead of mutating in place: asyncio tasks and copied contexts share this dict object
+    context_values = dict(context.get())
 
     for k in keys:
         context_values.pop(k, None)

tests/functional/logger/required_dependencies/test_logger_powertools_formatter.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import asyncio
 import io
 import json
 import os
@@ -486,6 +487,32 @@ def send_message_with_key_and_without(message, keys):
     assert logs[1].get("exampleThread1Key") is None
 
 
+def test_thread_safe_remove_keys_does_not_affect_tasks_sharing_the_context(service_name, stdout):
+    logger = Logger(
+        service=service_name,
+        stream=stdout,
+    )
+
+    async def process_order():
+        await asyncio.sleep(0)
+        logger.info("processing order")
+
+    async def main():
+        logger.thread_safe_append_keys(order_id="order-1")
+        task = asyncio.create_task(process_order())  # the task runs in a copy of the current context
+        logger.thread_safe_remove_keys(["order_id"])
+        await task
+        logger.info("caller after removing the key")
+
+    asyncio.run(main())
+
+    logs = capture_logging_output(stdout)
+
+    assert logs[0].get("message") == "processing order"
+    assert logs[0].get("order_id") == "order-1"
+    assert logs[1].get("order_id") is None
+
+
 def test_thread_safe_clear_key(service_name, stdout):
     logger = Logger(
         service=service_name,