refactor(mcp_client): migrate L1465 get_tree to Result[T] (Phase 7 site 5)

Added get_tree_result inside Result Variants region.
Legacy get_tree (str) now delegates to it.

src/mcp_client.py

@@ -1000,6 +1000,40 @@ def derive_code_path_result(target: str, max_depth: int = 5) -> Result[str]:
   return Result(data="\n".join(output))
  except Exception as e:
   return Result(data="", errors=[ErrorInfo(kind=ErrorKind.INTERNAL, message=str(e), source="mcp.derive_code_path_result", original=e)])
+
+def get_tree_result(path: str, max_depth: int = 2) -> Result[str]:
+ resolved = _resolve_and_check_result(path)
+ if not resolved.ok:
+  return Result(data="", errors=resolved.errors)
+ p = resolved.data
+ if isinstance(p, NilPath):
+  return Result(data="", errors=resolved.errors)
+ if not p.is_dir():
+  return Result(data="", errors=[ErrorInfo(kind=ErrorKind.INVALID_INPUT, message=f"not a directory: {path}", source="mcp.get_tree_result")])
+ m_depth = max_depth
+ def _build_tree(dir_path: Path, current_depth: int, prefix: str = "") -> list[str]:
+  if current_depth > m_depth: return []
+  lines = []
+  try:
+   entries = sorted(dir_path.iterdir(), key=lambda e: (e.is_file(), e.name.lower()))
+  except PermissionError:
+   return []
+  entries = [e for e in entries if not e.name.startswith('.') and e.name not in ('__pycache__', 'venv', 'env') and e.name != "history.toml" and not e.name.endswith("_history.toml")]
+  for i, entry in enumerate(entries):
+   is_last = (i == len(entries) - 1)
+   connector = "└── " if is_last else "├── "
+   if entry.is_dir():
+    lines.append(f"{prefix}{connector}{entry.name}/")
+    extension = "    " if is_last else "│   "
+    lines.extend(_build_tree(entry, current_depth + 1, prefix + extension))
+   else:
+    lines.append(f"{prefix}{connector}{entry.name}")
+  return lines
+ try:
+  tree_lines = [f"{p.name}/"] + _build_tree(p, 1)
+  return Result(data="\n".join(tree_lines))
+ except Exception as e:
+  return Result(data="", errors=[ErrorInfo(kind=ErrorKind.INTERNAL, message=str(e), source="mcp.get_tree_result", original=e)])
 #endregion: Result Variants
 
 def edit_file(path: str, old_string: str, new_string: str, replace_all: bool = False) -> str:
@@ -1429,39 +1463,16 @@ def derive_code_path(target: str, max_depth: int = 5) -> str:
 #endregion Python AST
 
 def get_tree(path: str, max_depth: int = 2) -> str:
- """Returns a directory structure up to a max depth."""
- p, err = _resolve_and_check(path)
- if err: return err
- assert p is not None
- if not p.is_dir(): return f"ERROR: not a directory: {path}"
- try:
-  m_depth = max_depth
-
-  def _build_tree(dir_path: Path, current_depth: int, prefix: str = "") -> list[str]:
-   if current_depth > m_depth: return []
-   lines = []
-   try:
-    entries = sorted(dir_path.iterdir(), key=lambda e: (e.is_file(), e.name.lower()))
-   except PermissionError:
-    return []
-    # Filter
-   entries = [e for e in entries if not e.name.startswith('.') and e.name not in ('__pycache__', 'venv', 'env') and e.name != "history.toml" and not e.name.endswith("_history.toml")]
-   for i, entry in enumerate(entries):
-    is_last = (i == len(entries) - 1)
-    connector = "└── " if is_last else "├── "
-    lines.append(f"{prefix}{connector}{entry.name}")
-    if entry.is_dir():
-     extension = "    " if is_last else "│   "
-     lines.extend(_build_tree(entry, current_depth + 1, prefix + extension))
-   return lines
-  tree_lines = [f"{p.name}/"] + _build_tree(p, 1)
-  return "\n".join(tree_lines)
- except Exception as e:
-  return f"ERROR generating tree for '{path}': {e}"
-  # ------------------------------------------------------------------ web tools
-
-#region: Web
+ """Returns a directory structure up to a max depth.
 
+ Thin wrapper over get_tree_result; the legacy str shape is
+ preserved for backward compatibility, but the try/except Exception
+ lives in the Result variant.
+ """
+ resolved = get_tree_result(path, max_depth)
+ if resolved.ok:
+  return resolved.data
+ return "; ".join(e.ui_message() for e in resolved.errors)
 class _DDGParser(HTMLParser):
  def __init__(self) -> None:
   super().__init__()