lib.ExecContext: Support bytes-typed cmd_input

The Input instance passed as cmd_input to ExecContext.run() and
.sudo() currently may be of type str. Allow to pass bytes, too.

At the same time, disallow None to be passed as cmd_input. Force the
caller to be more explicit how it wants input to be handled, notably
with respect to interactivity.

Along the way fix a bug: Content in cmd_input should result in
CallContext.interactive == False but doesn't. Fix that.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/lib/ExecContext.py

@@ -18,7 +18,7 @@ class InputMode(Enum):
     OptInteractive = auto()
     Auto = auto()
 
-Input: TypeAlias = InputMode | None | str
+Input: TypeAlias = InputMode | bytes | str
 
 class Result(NamedTuple):
 
@@ -61,19 +61,27 @@ class ExecContext(abc.ABC):
             # -- At the end of this dance, interactive needs to be either True
             # or False
             interactive: bool|None = None
-            match cmd_input:
-                case InputMode.Interactive:
-                    interactive = True
-                case InputMode.NonInteractive:
-                    interactive = False
-                case InputMode.OptInteractive:
+            if not isinstance(cmd_input, InputMode):
+                interactive = False
+                self.__cmd_input = (
+                    cmd_input if isinstance(cmd_input, bytes) else
+                    cmd_input.encode(sys.stdout.encoding or "utf-8")
+                )
+            else:
+                match cmd_input:
+                    case InputMode.Interactive:
+                        interactive = True
+                    case InputMode.NonInteractive:
+                        interactive = False
+                    case InputMode.OptInteractive:
+                        interactive = parent.interactive
+                    case InputMode.Auto:
+                        interactive = sys.stdin.isatty()
+                if interactive is None:
                     interactive = parent.interactive
-                case InputMode.Auto:
+                if interactive is None:
                     interactive = sys.stdin.isatty()
-            if interactive is None:
-                interactive = parent.interactive
-            if interactive is None:
-                interactive = sys.stdin.isatty()
+                self.__cmd_input = None
             assert interactive in [ True, False ]
             self.__interactive = interactive
 
@@ -106,7 +114,7 @@ class ExecContext(abc.ABC):
             return self.__verbose
 
         @property
-        def cmd_input(self) -> bool:
+        def cmd_input(self) -> bytes|None:
             return self.__cmd_input
 
         @property
@@ -211,6 +219,10 @@ class ExecContext(abc.ABC):
               In PTY mode stderr is always None because PTY merges stdout/stderr.
         """
 
+        # Note that in the calls to the wrapped method, cmd_input == None can
+        # be returned by CallContext and is very much allowed
+        assert cmd_input is not None
+
         ret = Result(None, None, 1)
         with self.CallContext(self, title=title, cmd=cmd, cmd_input=cmd_input, wd=wd,
                               log_prefix='|', throw=throw, verbose=verbose) as cc:
@@ -246,6 +258,10 @@ class ExecContext(abc.ABC):
         title: str=None,
     ) -> Result:
 
+        # Note that in the calls to the wrapped method, cmd_input == None can
+        # be returned by CallContext and is very much allowed
+        assert cmd_input is not None
+
         ret = Result(None, None, 1)
         if opts is None:
             opts = {}