Add test that confirms that the task is cancelled immedeately

tests/test_async_sparql_wrapper.py

@@ -1,9 +1,11 @@
+import asyncio
 import os
 from string import Template
 
 import pytest
 import t_utils.common as t_common
 
+from cimsparql.async_sparql_wrapper import retry_task
 from cimsparql.graphdb import make_async
 
 
@@ -31,3 +33,15 @@ async def test_async_rdf4j_picasso_data(query: str, expect: list[dict[str, str]]
     client = make_async(client)
     result = await client.exec_query(f"{prefixes}\n{query}")
     assert result == expect
+
+
+@pytest.mark.asyncio
+async def test_return_immediately_on_cancel():
+    async def task() -> None:
+        await asyncio.sleep(10.0)
+        raise RuntimeError("This task always fails")
+
+    retry_10_times_task = asyncio.create_task(retry_task(lambda: task(), 10, 2))
+    retry_10_times_task.cancel()
+    with pytest.raises(asyncio.CancelledError):
+        await retry_10_times_task