Update subprocess types and fix mypy issues in run.py - Add proper type annotations for stdout/stderr lines - Fix None checks for file descriptors - Update error messages to follow style guidelines - Improve error handling for subprocess calls

Author: tony

src/libvcs/_internal/run.py

@@ -24,6 +24,10 @@
 
 console_encoding = sys.stdout.encoding
 
+PIPE_NOT_SET_ERR = (
+    "File descriptor is None, which should not happen as we set PIPE as default"
+)
+
 
 def console_to_str(s: bytes) -> str:
     """From pypa/pip project, pip.backwardwardcompat. License MIT."""
@@ -226,12 +230,23 @@ def progress_cb(output: t.AnyStr, timestamp: datetime.datetime) -> None:
     if callback and callable(callback):
         callback(output="\r", timestamp=datetime.datetime.now())
 
-    lines = filter(None, (line.strip() for line in proc.stdout.readlines()))
-    all_output = console_to_str(b"\n".join(lines))
+    if proc.stdout is None:
+        raise RuntimeError(PIPE_NOT_SET_ERR)
+
+    stdout_lines: list[bytes] = [
+        line.strip() for line in proc.stdout.readlines() if line
+    ]
+    all_output = [console_to_str(b"\n".join(stdout_lines))]
+
     if code:
-        stderr_lines = filter(None, (line.strip() for line in proc.stderr.readlines()))
-        all_output = console_to_str(b"".join(stderr_lines))
+        if proc.stderr is None:
+            raise RuntimeError(PIPE_NOT_SET_ERR)
+        stderr_lines: list[bytes] = [
+            line.strip() for line in proc.stderr.readlines() if line
+        ]
+        all_output = [console_to_str(b"".join(stderr_lines))]
+
     output = "".join(all_output)
     if code != 0 and check_returncode:
-        raise exc.CommandError(output=output, returncode=code, cmd=args)
+        raise exc.CommandError(output=output, returncode=code, cmd=str(args))
     return output