Add FakeClient option to use randomized dispatch list

Some tests require extra checks to not rely on the order.

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

Author: Marenz

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

@@ -8,6 +8,7 @@
 import dataclasses
 from dataclasses import dataclass, replace
 from datetime import datetime, timezone
+from random import shuffle
 
 import grpc
 import grpc.aio
@@ -45,6 +46,9 @@ class FakeService:
     _last_id: int = 0
     """Last used dispatch id."""
 
+    _shuffle_after_create: bool = False
+    """Whether to shuffle the dispatches after creating them."""
+
     # pylint: disable=invalid-name
     async def ListMicrogridDispatches(
         self, request: PBDispatchListRequest
@@ -116,6 +120,9 @@ async def CreateMicrogridDispatch(
                 update_time=datetime.now(tz=timezone.utc),
             )
         )
+        if self._shuffle_after_create:
+            shuffle(self.dispatches)
+
         return Empty()
 
     async def UpdateMicrogridDispatch(

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

@@ -17,10 +17,15 @@ class FakeClient(Client):
     This client uses a fake service to simulate the dispatch api.
     """
 
-    def __init__(self) -> None:
-        """Initialize the mock client."""
+    def __init__(self, shuffle_after_create: bool = False) -> None:
+        """Initialize the mock client.
+
+        Args:
+            shuffle_after_create: Whether to shuffle the dispatches after creating them.
+        """
         super().__init__(MagicMock(), "mock")
         self._stub = FakeService()  # type: ignore
+        self._service._shuffle_after_create = shuffle_after_create
 
     @property
     def dispatches(self) -> list[Dispatch]: