interpreter: move command kwarg to type_checking

mesonbuild/interpreter/interpreter.py

@@ -50,6 +50,7 @@ from .interpreterobjects import (
     NullSubprojectInterpreter,
 )
 from .type_checking import (
+    COMMAND_KW,
     DEPENDS_KW,
     DEPFILE_KW,
     ENV_KW,
@@ -1669,14 +1670,7 @@ This will become a hard error in the future.''' % kwargs['input'], location=self
     @typed_pos_args('run_target', str)
     @typed_kwargs(
         'run_target',
-        KwargInfo(
-            'command',
-            # TODO: should accept CustomTargetIndex as well?
-            ContainerTypeInfo(list, (str, build.BuildTarget, build.CustomTarget, ExternalProgram, mesonlib.File), allow_empty=False),
-            required=True,
-            listify=True,
-            default=[],
-        ),
+        COMMAND_KW,
         DEPENDS_KW,
         ENV_KW.evolve(since='0.57.0'),
     )

mesonbuild/interpreter/type_checking.py

@@ -11,6 +11,7 @@ from ..coredata import UserFeatureOption
 from ..interpreterbase import TYPE_var
 from ..interpreterbase.decorators import KwargInfo, ContainerTypeInfo
 from ..mesonlib import File, FileMode, MachineChoice, listify, has_path_sep
+from ..programs import ExternalProgram
 
 # Helper definition for type checks that are `Optional[T]`
 NoneType: T.Type[None] = type(None)
@@ -197,3 +198,12 @@ DEPEND_FILES_KW: KwargInfo[T.List[T.Union[str, File]]] = KwargInfo(
     listify=True,
     default=[],
 )
+
+COMMAND_KW: KwargInfo[T.List[T.Union[BuildTarget, CustomTarget, ExternalProgram, File]]] = KwargInfo(
+    'command',
+    # TODO: should accept CustomTargetIndex as well?
+    ContainerTypeInfo(list, (str, BuildTarget, CustomTarget, ExternalProgram, File), allow_empty=False),
+    required=True,
+    listify=True,
+    default=[],
+)