Fix checks in tests

The checks in the data sourcing actor were meant to check if the value
of the sample was `None`, not the sample itself (as the type system
guarantees that `sample` will never be `None`.

This issue wasn't detected because the `ChannelRegistry` used `Any` as
message type, so `sample` had type `Any`, which means that as far as
the type system is concerned, it could have been `None`.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

tests/actor/test_data_sourcing.py

@@ -83,15 +83,15 @@ async def test_data_sourcing_actor(self) -> None:
 
             for _ in range(3):
                 sample = await soc_recv.receive()
-                assert sample is not None
+                assert sample.value is not None
                 assert 9.0 == sample.value.base_value
 
                 sample = await soc2_recv.receive()
-                assert sample is not None
+                assert sample.value is not None
                 assert 9.0 == sample.value.base_value
 
                 sample = await active_power_recv.receive()
-                assert sample is not None
+                assert sample.value is not None
                 assert 100.0 == sample.value.base_value
 
             assert await server.graceful_shutdown()