Stores and drafts

A signal holds one value. A store holds an object or array and tracks each property separately, so a change to one todo's done updates only the parts of the page that read it.

Read a store like a plain object, with no getter call. Write it through its setter, which hands you a draft to change:

const [todos, setTodos] = createStore([]);

setTodos((draft) => {
  const todo = draft.find((todo) => todo.id === id);
  if (todo) todo.done = !todo.done;
});

The setter can also return a new value instead, which Solid merges into the store by each item's id:

setTodos((list) => list.filter((todo) => !todo.done));

Outside the setter, treat the store as read-only.

Try it: adding already works. Make the checkboxes toggle done through a draft, and make Clear done remove finished todos by returning a filtered list.