Add type hints to Service properties

Author: CarstenGrohmann

Diff for: testinfra/modules/service.py

@@ -11,6 +11,7 @@
 # limitations under the License.
 
 import functools
+from typing import Any
 
 from testinfra.modules.base import Module
 
@@ -34,22 +35,22 @@ def __init__(self, name):
         super().__init__()
 
     @property
-    def exists(self):
+    def exists(self) -> bool:
         """Test if the service exists"""
         raise NotImplementedError
 
     @property
-    def is_running(self):
+    def is_running(self) -> bool:
         """Test if service is running"""
         raise NotImplementedError
 
     @property
-    def is_enabled(self):
+    def is_enabled(self) -> bool:
         """Test if service is enabled"""
         raise NotImplementedError
 
     @property
-    def is_valid(self):
+    def is_valid(self) -> bool:
         """Test if service is valid
 
         This method is only available in the systemd implementation,
@@ -58,7 +59,7 @@ def is_valid(self):
         raise NotImplementedError
 
     @property
-    def is_masked(self):
+    def is_masked(self) -> bool:
         """Test if service is masked
 
         This method is only available in the systemd implementation,
@@ -67,7 +68,7 @@ def is_masked(self):
         raise NotImplementedError
 
     @functools.cached_property
-    def systemd_properties(self):
+    def systemd_properties(self) -> dict[str, Any]:
         """Properties of the service (unit).
 
         Return service properties as a `dict`,