Address review comments

testinfra/backend/base.py

@@ -17,7 +17,7 @@
 import shlex
 import subprocess
 import urllib.parse
-from typing import TYPE_CHECKING, Any, Optional
+from typing import TYPE_CHECKING, Any, Optional, Union
 
 if TYPE_CHECKING:
     import testinfra.host
@@ -35,12 +35,11 @@ class HostSpec:
 
 @dataclasses.dataclass
 class CommandResult:
+    backend: "BaseBackend"
     exit_status: int
     command: bytes
-    stdout_bytes: bytes
-    stderr_bytes: bytes
-    stdout: str
-    stderr: str
+    _stdout: Union[str, bytes]
+    _stderr: Union[str, bytes]
 
     @property
     def succeeded(self) -> bool:
@@ -69,6 +68,30 @@ def rc(self) -> int:
         """
         return self.exit_status
 
+    @property
+    def stdout(self) -> str:
+        if isinstance(self._stdout, bytes):
+            return self.backend.decode(self._stdout)
+        return self._stdout
+
+    @property
+    def stderr(self) -> str:
+        if isinstance(self._stderr, bytes):
+            return self.backend.decode(self._stderr)
+        return self._stderr
+
+    @property
+    def stdout_bytes(self) -> bytes:
+        if isinstance(self._stdout, str):
+            return self.backend.encode(self._stdout)
+        return self._stdout
+
+    @property
+    def stderr_bytes(self) -> bytes:
+        if isinstance(self._stderr, str):
+            return self.backend.encode(self._stderr)
+        return self._stderr
+
 
 class BaseBackend(metaclass=abc.ABCMeta):
     """Represent the connection to the remote or local system"""
@@ -258,34 +281,30 @@ def encode(self, data: str) -> bytes:
     def result(self, *args: Any, **kwargs: Any) -> CommandResult:
         rc, cmd = args[:2]
 
+        out, err = "", ""
         out_bytes, err_bytes = b"", b""
         if len(args) > 2:
-            out_bytes = args[2]
+            if isinstance(args[2], bytes):
+                out_bytes = args[2]
+            else:
+                out = args[2]
         if len(args) > 3:
-            err_bytes = args[3]
+            if isinstance(args[3], bytes):
+                err_bytes = args[3]
+            else:
+                err = args[3]
 
         out_bytes = kwargs.get("stdout_bytes", out_bytes)
         err_bytes = kwargs.get("stderr_bytes", err_bytes)
-
-        out = kwargs.get("stdout", "")
-        if not out and out_bytes:
-            out = self.decode(out_bytes)
-        elif out and not out_bytes:
-            out_bytes = self.encode(out)
-
-        err = kwargs.get("stderr", "")
-        if not err and err_bytes:
-            err = self.decode(err_bytes)
-        elif err and not err_bytes:
-            err_bytes = self.encode(err)
+        out = kwargs.get("stdout", out)
+        err = kwargs.get("stderr", err)
 
         result = CommandResult(
+            backend=self,
             exit_status=rc,
             command=cmd,
-            stderr=err,
-            stderr_bytes=err_bytes,
-            stdout=out,
-            stdout_bytes=out_bytes,
+            _stdout=out_bytes or out,
+            _stderr=err_bytes or err,
         )
         logger.debug("RUN %s", result)
         return result