fix(tools): harden todo renderer and blank-title normalization

Treat blank titles as missing for Cursor-shape detection, compute indent
from ANSI-stripped text, and show invalid args for malformed complete lists.

Author: elkaix

src/pythinker_code/tools/todo/__init__.py

@@ -25,7 +25,7 @@ def normalize_set_todo_list_args(args: dict[str, Any]) -> dict[str, Any]:
     """Accept Cursor/Claude TodoWrite shape while keeping internal state canonical.
 
     Supported external aliases:
-    - ``content`` -> ``title``, only when ``title`` is missing
+    - ``content`` -> ``title``, only when ``title`` is missing or blank
 
     Deliberately does not:
     - invent titles
@@ -48,8 +48,9 @@ def normalize_set_todo_list_args(args: dict[str, Any]) -> dict[str, Any]:
 
         title = item.get("title")
         content = item.get("content")
+        title_missing = title is None or (isinstance(title, str) and not title.strip())
 
-        if title is None and content is not None:
+        if title_missing and content is not None:
             item["title"] = content
 
         item.pop("content", None)

src/pythinker_code/ui/shell/tool_renderers/todo.py

@@ -52,16 +52,22 @@
 
 
 def _has_cursor_todowrite_shape(args: dict[str, Any]) -> bool:
-    """True when args look like Cursor/Claude TodoWrite ({content} without {title})."""
+    """True when args look like Cursor/Claude TodoWrite ({content} without usable {title})."""
     todos = args.get("todos")
     if not isinstance(todos, list):
         return False
+
     for raw in cast("list[Any]", todos):
         if not isinstance(raw, dict):
             continue
+
         item = cast(dict[str, Any], raw)
-        if "content" in item and "title" not in item:
+        title = (as_str(item.get("title")) or "").strip()
+        content = (as_str(item.get("content")) or "").strip()
+
+        if content and not title:
             return True
+
     return False
 
 
@@ -102,13 +108,15 @@ def _clean_todo_title(raw_title: str) -> str:
 def _todo_level_and_title(item: dict[str, Any]) -> tuple[int, str]:
     """Return display nesting level and a cleaned title."""
     raw_title = as_str(item.get("title")) or as_str(item.get("content")) or ""
+    safe_title = sanitize_ansi(raw_title)
+
     explicit = item.get("level", item.get("depth", item.get("indent")))
-    cleaned = _clean_todo_title(raw_title)
+    cleaned = _clean_todo_title(safe_title)
 
     if isinstance(explicit, int):
         return max(0, min(explicit, 6)), cleaned
 
-    leading_spaces = len(raw_title) - len(raw_title.lstrip(" "))
+    leading_spaces = len(safe_title) - len(safe_title.lstrip(" "))
     level = max(0, min(leading_spaces // 2, 6))
     return level, cleaned
 
@@ -162,6 +170,15 @@ def _render_call(ctx: ToolRenderContext) -> RenderableType:
         )
 
     todos_list = cast("list[Any]", todos)
+    has_malformed_items = any(not isinstance(t, dict) for t in todos_list)
+    if has_malformed_items and (ctx.args_complete or ctx.has_result):
+        header = tool_call_header("todos", invalid_arg(), style_token=style_token)
+        return running_spinner(
+            header,
+            execution_started=ctx.execution_started,
+            has_result=ctx.has_result,
+        )
+
     items: list[dict[str, Any]] = [
         cast("dict[str, Any]", t) for t in todos_list if isinstance(t, dict)
     ]

tests/tools/test_todo.py

@@ -62,6 +62,22 @@ def test_normalizer_does_not_mutate_input(self):
         normalize_set_todo_list_args(args)
         assert args == original
 
+    def test_blank_title_with_content_normalizes_to_title(self):
+        args = {
+            "todos": [{"title": "", "content": "Install framer-motion", "status": "pending"}]
+        }
+        out = normalize_set_todo_list_args(args)
+        assert out["todos"][0]["title"] == "Install framer-motion"
+        assert "content" not in out["todos"][0]
+
+    def test_params_mixed_non_dict_item_fails_validation(self):
+        from pydantic import ValidationError
+
+        with pytest.raises(ValidationError):
+            Params(  # type: ignore[arg-type]
+                todos=[{"title": "ok", "status": "pending"}, "bad"]
+            )
+
     def test_missing_title_still_fails_after_normalization(self):
         args = {"todos": [{"id": "1", "status": "pending"}]}
         out = normalize_set_todo_list_args(args)

tests/ui_and_conv/test_tui_card_tool_renderers.py

@@ -31,6 +31,7 @@
 from pythinker_code.ui.shell.tool_renderers.generic import generic_renderer
 from pythinker_code.ui.shell.tool_renderers.todo import (
     TODO_RENDERER,
+    _has_cursor_todowrite_shape,
     _summarize_todo_validation_error,
     _todo_level_and_title,
 )
@@ -1200,6 +1201,43 @@ def test_todo_validation_error_shows_full_detail_when_expanded():
     assert "Field required" in rendered
 
 
+def test_cursor_shape_detects_blank_title_with_content():
+    args = {"todos": [{"title": "", "content": "Install framer-motion", "status": "pending"}]}
+    assert _has_cursor_todowrite_shape(args) is True
+
+
+def test_renderer_blank_title_uses_content_fallback():
+    _level, title = _todo_level_and_title(
+        {"title": "", "content": "Install framer-motion", "status": "pending"}
+    )
+    assert title == "Install framer-motion"
+
+
+def test_renderer_indent_ignores_ansi_before_leading_spaces():
+    raw = "\x1b[31m  \x1b[0mNested task"
+    _level, title = _todo_level_and_title({"title": raw, "status": "pending"})
+    assert _level == 1
+    assert title == "Nested task"
+
+
+def test_malformed_todos_list_renders_invalid_when_args_complete():
+    rendered = _render_running(
+        "SetTodoList",
+        {"todos": ["bad", None, 123, {"title": "ok", "status": "pending"}]},
+    )
+    assert "<invalid>" in rendered
+    assert "ok" not in rendered
+
+
+def test_malformed_todos_streaming_skips_non_dict_items():
+    rendered = _render_streaming(
+        "SetTodoList",
+        {"todos": ["bad", {"title": "Visible", "status": "pending"}]},
+    )
+    assert "<invalid>" not in rendered
+    assert "Visible" in rendered
+
+
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