In superclass __enter__ method is defined with return value type hint
'QEMUMachine'. So, mypy thinks that return value of VM.__enter__ is
QEMUMachine. Let's redefine __enter__ in VM class, to give it correct
type hint.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/iotests.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 777fa2ec0e..c7ec16c082 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -568,6 +568,10 @@ def remote_filename(path):
 class VM(qtest.QEMUQtestMachine):
     '''A QEMU VM'''
 
+    # Redefine __enter__ with proper type hint
+    def __enter__(self) -> 'VM':
+        return self
+
     def __init__(self, path_suffix=''):
         name = "qemu%s-%d" % (path_suffix, os.getpid())
         super().__init__(qemu_prog, qemu_opts, name=name,
-- 
2.29.2

On 20.05.21 16:21, Vladimir Sementsov-Ogievskiy wrote:
> In superclass __enter__ method is defined with return value type hint
> 'QEMUMachine'. So, mypy thinks that return value of VM.__enter__ is
> QEMUMachine. Let's redefine __enter__ in VM class, to give it correct
> type hint.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>   tests/qemu-iotests/iotests.py | 4 ++++
>   1 file changed, 4 insertions(+)

Reviewed-by: Max Reitz <mreitz@redhat.com>