Fix last_id in fake service when setting dispatches

Signed-off-by: Mathias L. Baumann <[email protected]>

Author: Marenz

RELEASE_NOTES.md

@@ -3,3 +3,5 @@
 ## Bug Fixes
 
 * Fix missing dependency in last release
+* The `FakeClient.set_dispatches()` method now correctly updates `FakeService._last_id` which is used to generate unique dispatch IDs.
+

src/frequenz/client/dispatch/test/client.py

@@ -54,6 +54,16 @@ def set_dispatches(self, microgrid_id: int, value: list[Dispatch]) -> None:
         """
         self._service.dispatches[microgrid_id] = value
 
+        if len(value) == 0:
+            return
+
+        # Max between last id and the max id in the list
+        # pylint: disable=protected-access
+        self._service._last_id = max(
+            self._service._last_id, max(dispatch.id for dispatch in value)
+        )
+        # pylint: enable=protected-access
+
     @property
     def _service(self) -> FakeService:
         """The fake service.