improve limit tests with parallelized case

tests/extract/test_sources.py

@@ -839,26 +839,32 @@ def test_limit_infinite_counter() -> None:
 
 @pytest.mark.parametrize("limit", (None, -1, 0, 10))
 def test_limit_edge_cases(limit: int) -> None:
-    r = dlt.resource(range(20), name="infinity").add_limit(limit)  # type: ignore
+    r = dlt.resource(range(20), name="resource").add_limit(limit)  # type: ignore
 
     @dlt.resource()
     async def r_async():
         for i in range(20):
             await asyncio.sleep(0.01)
             yield i
 
+    @dlt.resource(parallelized=True)
+    def parallelized_resource():
+        for i in range(20):
+            yield i
+
     sync_list = list(r)
     async_list = list(r_async().add_limit(limit))
+    parallelized_list = list(parallelized_resource().add_limit(limit))
+
+    # all lists should be the same
+    assert sync_list == async_list == parallelized_list
 
     if limit == 10:
         assert sync_list == list(range(10))
-        # we have edge cases where the async list will have one extra item
-        # possibly due to timing issues, maybe some other implementation problem
-        assert (async_list == list(range(10))) or (async_list == list(range(11)))
     elif limit in [None, -1]:
-        assert sync_list == async_list == list(range(20))
+        assert sync_list == list(range(20))
     elif limit == 0:
-        assert sync_list == async_list == []
+        assert sync_list == []
     else:
         raise AssertionError(f"Unexpected limit: {limit}")