fix: handle todo_write string inputs for issue 340

Co-authored-by: gui-yue <yuemeng.gui@gmail.com>

tests/test_todo_write_string_input.py

@@ -0,0 +1,115 @@
+import importlib.util
+import os
+import sys
+import tempfile
+import types
+import unittest
+from pathlib import Path
+
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+COURSE_MODULES = [
+    ("s05", REPO_ROOT / "s05_todo_write" / "code.py"),
+    ("s06", REPO_ROOT / "s06_subagent" / "code.py"),
+    ("s07", REPO_ROOT / "s07_skill_loading" / "code.py"),
+    ("s08", REPO_ROOT / "s08_context_compact" / "code.py"),
+    ("s20", REPO_ROOT / "s20_comprehensive" / "code.py"),
+]
+
+
+def load_course_module(module_name: str, module_path: Path, temp_cwd: Path):
+    fake_anthropic = types.ModuleType("anthropic")
+
+    class FakeAnthropic:
+        def __init__(self, *args, **kwargs):
+            self.messages = types.SimpleNamespace(create=None)
+
+    fake_dotenv = types.ModuleType("dotenv")
+    fake_yaml = types.ModuleType("yaml")
+    setattr(fake_anthropic, "Anthropic", FakeAnthropic)
+    setattr(fake_dotenv, "load_dotenv", lambda override=True: None)
+    setattr(fake_yaml, "safe_load", lambda text: {})
+    setattr(fake_yaml, "YAMLError", Exception)
+
+    previous_modules = {
+        "anthropic": sys.modules.get("anthropic"),
+        "dotenv": sys.modules.get("dotenv"),
+        "yaml": sys.modules.get("yaml"),
+    }
+    previous_cwd = Path.cwd()
+    previous_model_id = os.environ.get("MODEL_ID")
+
+    spec = importlib.util.spec_from_file_location(f"{module_name}_todo_test", module_path)
+    if spec is None or spec.loader is None:
+        raise RuntimeError(f"Unable to load {module_path}")
+    module = importlib.util.module_from_spec(spec)
+
+    sys.modules["anthropic"] = fake_anthropic
+    sys.modules["dotenv"] = fake_dotenv
+    sys.modules["yaml"] = fake_yaml
+    try:
+        os.chdir(temp_cwd)
+        os.environ["MODEL_ID"] = "test-model"
+        spec.loader.exec_module(module)
+        return module
+    finally:
+        os.chdir(previous_cwd)
+        if previous_model_id is None:
+            os.environ.pop("MODEL_ID", None)
+        else:
+            os.environ["MODEL_ID"] = previous_model_id
+        for name, previous in previous_modules.items():
+            if previous is None:
+                sys.modules.pop(name, None)
+            else:
+                sys.modules[name] = previous
+
+
+class TodoWriteStringInputTests(unittest.TestCase):
+    def test_issue_340_accepts_json_array_string(self):
+        for module_name, module_path in COURSE_MODULES:
+            with self.subTest(module=module_name), tempfile.TemporaryDirectory() as tmp:
+                module = load_course_module(module_name, module_path, Path(tmp))
+
+                result = module.run_todo_write(
+                    '[{"content": "inspect repo", "status": "pending"}]'
+                )
+
+                self.assertIn("Updated 1", result)
+                self.assertEqual(
+                    module.CURRENT_TODOS,
+                    [{"content": "inspect repo", "status": "pending"}],
+                )
+
+    def test_issue_340_accepts_python_list_repr_string(self):
+        for module_name, module_path in COURSE_MODULES:
+            with self.subTest(module=module_name), tempfile.TemporaryDirectory() as tmp:
+                module = load_course_module(module_name, module_path, Path(tmp))
+
+                result = module.run_todo_write(
+                    "[{'content': 'write tests', 'status': 'in_progress'}]"
+                )
+
+                self.assertIn("Updated 1", result)
+                self.assertEqual(
+                    module.CURRENT_TODOS,
+                    [{"content": "write tests", "status": "in_progress"}],
+                )
+
+    def test_issue_340_does_not_eval_string_inputs(self):
+        for module_name, module_path in COURSE_MODULES:
+            with self.subTest(module=module_name), tempfile.TemporaryDirectory() as tmp:
+                tmp_path = Path(tmp)
+                marker = tmp_path / "eval_was_executed"
+                module = load_course_module(module_name, module_path, tmp_path)
+
+                result = module.run_todo_write(
+                    f"__import__('pathlib').Path({str(marker)!r}).write_text('bad')"
+                )
+
+                self.assertIn("Error:", result)
+                self.assertFalse(marker.exists())
+
+
+if __name__ == "__main__":
+    unittest.main()