todos-function-component.tsx

const TodosApp = () => {

  // Declare every state we need to store
  const [filter, setFilter] = React.useState<TodoState["filter"]>("All");
  const [todos, setTodo] = React.useState<TodoState["todos"]>([]);
  const [textInput, setTextInput] = React.useState<TodoState["textInput"]("");
                                                              
                                                              
                                                               
  return ( /** implement UI */ )
}