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>
Reviewed-by: Max Reitz <mreitz@redhat.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 89663dac06..025e288ddd 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
First and foremost:
A more durable approach might be to annotate QEMUMachine differently such that subclasses get the right types automatically. See if this following snippet works instead of adding a new __enter__ method.
diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py
index 971ed7e8c6a..2e410103569 100644
--- a/python/qemu/machine/machine.py
+++ b/python/qemu/machine/machine.py
@@ -36,6 +36,7 @@
Sequence,
Tuple,
Type,
+ TypeVar,
)
from qemu.qmp import ( # pylint: disable=import-error
@@ -73,6 +74,9 @@ class AbnormalShutdown(QEMUMachineError):
"""
+_T = TypeVar('_T', bound='QEMUMachine')
+
+
class QEMUMachine:
"""
A QEMU VM.
@@ -166,7 +170,7 @@ def __init__(self,
self._remove_files: List[str] = []
self._user_killed = False
- def __enter__(self) -> 'QEMUMachine':
+ def __enter__(self: _T) -> _T:
return self
def __exit__(self,
@@ -182,8 +186,8 @@ def add_monitor_null(self) -> None:
self._args.append('-monitor')
self._args.append('null')
- def add_fd(self, fd: int, fdset: int,
- opaque: str, opts: str = '') -> 'QEMUMachine':
+ def add_fd(self: _T, fd: int, fdset: int,
+ opaque: str, opts: str = '') -> _T:
"""
Pass a file descriptor to the VM
"""