Notice that addTodoV2 and addTodoV3 error for extra field WRONG_FIELD, but addTodoV1 doesn't error for extra field in line 45.
TypeScript return Type inference issue in function type
Kenan Hançer Blog
Software Adventures
Notice that addTodoV2 and addTodoV3 error for extra field WRONG_FIELD, but addTodoV1 doesn't error for extra field in line 45.