反应还原剂不会变质

Question

I got this insane problem that I think has more to do about pure JS rather than redux.

My initial state looks like this:

let data = {
    outputs : ["0", "0", "0", "0"],
    analogIn : "0"
}

and this is part of my reducer so when I try to change a value of the outputs array (eg the 3rd value)

let newstate = Object.assign({}, state);
    switch (action.type) {
        case 'CLICK_OUTPUT':
            let outputs = newstate.outputs
            let status = outputs[action.num]
            let newStatus = (status == "0") ? "1" : "0"
            outputs[action.num] = newStatus
            newstate.outputs = outputs
            console.log(newstate.outputs[action.num])    <-- 1.
            console.log(newstate.outputs)                <-- 2. 
            console.log(newstate)                        <-- 3.
            return newstate
        default:
            return state || data.data
}

1. Returns "1" which is correct
2. Returns ["0", "0", "1", "0"] which is correct

3. Returns

   analogIn : "0", outputs : ["0", "0", "0", "0"]

so the state is not changed...

When I try to change the analogIn it works

case 'CHANGE_IN':
    newstate.analogIn = action.val
    return newstate

Any ideas why does this happen? Does it have to do with redux?

Answer 1

Ok, found the solution.

As it seems using this:

newstate.outputs = outputs

or this:

newstate.outputs[num] = "1"

does not work if you want to copy the contents of one array to the value of an object that is an array

The solution was to clone the array

newstate.outputs = outputs.slice(0)

I'm not sure if this occured because of es6 or it is pure JS.