If there is a flex item with such flexbox values set to it flex: 1 0 220px; can I get by the means of javascript its dimensions (width, height) that would be applied to it when the values become flex: 1 0 auto;?

Is the only way to get these dimensions to set flex: 1 0 auto; to the item at first and only then call the needed javascript api method?

My issue is to (smoothly) switch flex items’ width values from the fixed 220px to the maximum auto among them. However, I don’t know how to obtain this maximum before auto is actually set.