fix: render bytes arguments as text instead of repr

local['echo'](b'test') passed b"test" through str(), so the child process
received the literal repr b'test' rather than test. Command arguments now
go through a _stringify helper that decodes bytes with os.fsdecode, which
shquote and the unquoted formulate paths both use.

Closes #600

Author: Sanjays2402

plumbum/commands/base.py

@@ -12,6 +12,7 @@
 
 import contextlib
 import functools
+import os
 import shlex
 import subprocess
 import typing
@@ -69,10 +70,20 @@ class RedirectionError(Exception):
 # ===================================================================================================
 # Utilities
 # ===================================================================================================
+def _stringify(value: Any) -> str:
+    """Renders a command-line argument as text.
+
+    ``bytes`` are decoded with :func:`os.fsdecode` rather than going through
+    ``str()``, which would render them as their ``repr`` (``b'test'``).
+    """
+    if isinstance(value, (bytes, bytearray, memoryview)):
+        return os.fsdecode(bytes(value))
+    return str(value)
+
+
 def shquote(text: Any) -> str:
     """Quotes the given text with shell escaping (assumes as syntax similar to ``sh``)"""
-    text = str(text)
-    return shlex.quote(text)
+    return shlex.quote(_stringify(text))
 
 
 def shquote_list(seq: Sequence[Any]) -> list[str]:
@@ -695,10 +706,11 @@ def formulate(self, level: int = 0, args: Sequence[Any] = ()) -> list[str]:
                     argv.extend(a.formulate(level + 1))
             elif isinstance(a, (list, tuple)):
                 argv.extend(
-                    shquote(b) if level >= self.QUOTE_LEVEL else str(b) for b in a
+                    shquote(b) if level >= self.QUOTE_LEVEL else _stringify(b)
+                    for b in a
                 )
             else:
-                argv.append(shquote(a) if level >= self.QUOTE_LEVEL else str(a))
+                argv.append(shquote(a) if level >= self.QUOTE_LEVEL else _stringify(a))
         return argv
 
     @property

tests/test_local.py

@@ -1322,3 +1322,24 @@ def test_is_recursive_glob(pattern, expected):
     from plumbum.machines.remote import _is_recursive_glob
 
     assert _is_recursive_glob(pattern) is expected
+
+
+class TestBytesArguments:
+    """``bytes`` arguments must be decoded, not rendered via ``repr``.
+
+    See https://github.com/tomerfiliba/plumbum/issues/600
+    """
+
+    def test_shquote_bytes(self):
+        from plumbum.commands import shquote
+
+        assert shquote(b"test") == "test"
+        assert shquote(b"a b") == "'a b'"
+
+    @skip_on_windows
+    def test_bytes_argument(self):
+        assert local["echo"](b"test").strip() == "test"
+
+    @skip_on_windows
+    def test_bytes_argument_in_list(self):
+        assert local["echo"][[b"a", b"b"]]().split() == ["a", "b"]