Did not understant this operator on array

Tell us what’s happening:
Describe your issue in detail here.

  **Your code so far**

const immutableReducer = (state = ['Do not mutate state!'], action) => {
switch(action.type) {
  case 'ADD_TO_DO':
    // Don't mutate state here or the tests will fail
    return state = [...state, "ADD_TO_DO"]
    return state;

const addToDo = (todo) => {
return {
  type: 'ADD_TO_DO',

const store = Redux.createStore(immutableReducer);
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Challenge: Use the Spread Operator on Arrays

Link to the challenge:

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You are using the spread syntax correctly you are just not adding the todo after it.

Looking at this object returned from the action creator…

return {
  type: 'ADD_TO_DO',

…if the type is action.type what is the todo?

return [...state, addTheTodoHere]