ci: add deployment workflow and automated tests

tests/test_todocreate.py

@@ -0,0 +1,28 @@
+import pytest
+from pydantic import ValidationError
+
+from main import todocreate
+
+
+def test_todocreate_requires_task() -> None:
+    with pytest.raises(ValidationError):
+        todocreate()
+
+def test_todocreate_accepts_valid_task() -> None:
+    todo_data = todocreate(task = "学习测试单元")
+    
+    assert todo_data.task == "学习测试单元"
+
+def test_todocreate_rejects_empty_task() -> None:
+    with pytest.raises(ValidationError):
+        todocreate(task="")
+
+def test_todocreate_rejects_blank_task() -> None:
+    with pytest.raises(ValidationError):
+        todocreate(task="   ")
+
+def test_todocreate_rejects_task_longer_than_200_characters() -> None:
+    long_task = "a" * 201
+
+    with pytest.raises(ValidationError):
+        todocreate(task=long_task)