refactor(mcp_client): migrate L1334 py_get_docstring to Result[T] (Phase 7 site 2)

Added py_get_docstring_result inside Result Variants region.
Legacy py_get_docstring (str) now delegates to it.

src/mcp_client.py

@@ -911,6 +911,31 @@ def py_check_syntax_result(path: str) -> Result[str]:
   return Result(data="", errors=[ErrorInfo(kind=ErrorKind.INVALID_INPUT, message=f"SyntaxError in {path} at line {e.lineno}, offset {e.offset}: {e.msg}\n{e.text}", source="mcp.py_check_syntax_result")])
  except Exception as e:
   return Result(data="", errors=[ErrorInfo(kind=ErrorKind.INTERNAL, message=str(e), source="mcp.py_check_syntax_result", original=e)])
+
+def py_get_docstring_result(path: str, name: str) -> 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_file() or p.suffix != ".py":
+  return Result(data="", errors=[ErrorInfo(kind=ErrorKind.INVALID_INPUT, message=f"not a python file: {path}", source="mcp.py_get_docstring_result")])
+ try:
+  code = p.read_text(encoding="utf-8")
+  tree = ast.parse(code)
+  if not name or name == "module":
+   doc = ast.get_docstring(tree)
+   return Result(data=doc if doc else "No module docstring found.")
+  node = _get_symbol_node(tree, name)
+  if not node:
+   return Result(data="", errors=[ErrorInfo(kind=ErrorKind.NOT_FOUND, message=f"could not find symbol '{name}' in {path}", source="mcp.py_get_docstring_result")])
+  if isinstance(node, (ast.AsyncFunctionDef, ast.FunctionDef, ast.ClassDef, ast.Module)):
+   doc = ast.get_docstring(node)
+   return Result(data=doc if doc else f"No docstring found for '{name}'.")
+  return Result(data=f"No docstring found for '{name}'.")
+ except Exception as e:
+  return Result(data="", errors=[ErrorInfo(kind=ErrorKind.INTERNAL, message=str(e), source="mcp.py_get_docstring_result", original=e)])
 #endregion: Result Variants
 
 def edit_file(path: str, old_string: str, new_string: str, replace_all: bool = False) -> str:
@@ -1314,25 +1339,16 @@ def py_get_hierarchy(path: str, class_name: str) -> str:
  return "; ".join(e.ui_message() for e in resolved.errors)
 
 def py_get_docstring(path: str, name: str) -> str:
- """Extracts the docstring for a specific module, class, or function."""
- p, err = _resolve_and_check(path)
- if err: return err
- assert p is not None
- if not p.is_file() or p.suffix != ".py": return f"ERROR: not a python file: {path}"
- try:
-  code = p.read_text(encoding="utf-8")
-  tree = ast.parse(code)
-  if not name or name == "module":
-   doc = ast.get_docstring(tree)
-   return doc if doc else "No module docstring found."
-  node = _get_symbol_node(tree, name)
-  if not node: return f"ERROR: could not find symbol '{name}' in {path}"
-  if isinstance(node, (ast.AsyncFunctionDef, ast.FunctionDef, ast.ClassDef, ast.Module)):
-   doc = ast.get_docstring(node)
-   return doc if doc else f"No docstring found for '{name}'."
-  return f"No docstring found for '{name}'."
- except Exception as e:
-  return f"ERROR getting docstring for '{name}': {e}"
+ """Extracts the docstring for a specific module, class, or function.
+
+ Thin wrapper over py_get_docstring_result; the legacy str shape is
+ preserved for backward compatibility, but the try/except Exception
+ lives in the Result variant.
+ """
+ resolved = py_get_docstring_result(path, name)
+ if resolved.ok:
+  return resolved.data
+ return "; ".join(e.ui_message() for e in resolved.errors)
 
 def derive_code_path(target: str, max_depth: int = 5) -> str:
  """Recursively traces the execution path of a specific function or method."""