iotests.py: Fix type check errors in wait_migration()

Commit 1847a4a8c20 clarified that event_wait() can return None (though
only with timeout=0) and commit f12a282ff47 annotated it as returning
Optional[QMPMessage].

Type checks in wait_migration() fail because of the unexpected optional
return type:

iotests.py:750: error: Value of type variable "Msg" of "log" cannot be "Optional[Dict[str, Any]]"
iotests.py:751: error: Value of type "Optional[Dict[str, Any]]" is not indexable
iotests.py:754: error: Value of type "Optional[Dict[str, Any]]" is not indexable

Fortunately, the non-zero default timeout is used in the event_wait()
call, so we can make mypy happy by just asserting this.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201027163806.290960-2-kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 63d2ace93c028b95ceca1cec3eab01ff250d7e84..28388a0fbc9ffa0b24fff65c43ba793bfa0cd7a4 100644 (file)
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -747,6 +747,10 @@ class VM(qtest.QEMUQtestMachine):
     def wait_migration(self, expect_runstate: Optional[str]) -> bool:
         while True:
             event = self.event_wait('MIGRATION')
+            # We use the default timeout, and with a timeout, event_wait()
+            # never returns None
+            assert event
+
             log(event, filters=[filter_qmp_event])
             if event['data']['status'] in ('completed', 'failed'):
                 break