Disabled items are highlighted when select is opened with Arrow Up/Down

[Eldraed]

• downshift version: 6.1.3
• node version: 14.17.3
• npm (or yarn) version: npm 6.14.13

Relevant code or config

Example taken from my reproduction :

<ul {...getMenuProps()} style={menuStyles}>
  {isOpen &&
    items.map((item, index) => (
      <li
        style={{
          ...(highlightedIndex === index
            ? {backgroundColor: '#bde4ff'}
            : {}),
          // First and last elements are disabled
          ...(index === 0 || index === items.length - 1
            ? {opacity: 0.6}
            : {}),
        }}
        key={`${item}${index}`}
        {...getItemProps({
          item,
          index,
          disabled: index === 0 || index === items.length - 1,
        })}
      >
        {item}
      </li>
    ))}
</ul>

I just consider that my first and last elements in my list are disabled.

What you did:
I have a list of items with some of them disabled. I want to navigate through my enabled items only with keyboard.

What happened:
With useSelect (the only one i use):
When i use my keyboard for navigation, with focus on my Toggle button, if i press Arrow up/down to open the list, first or last element will be highlighted even if it's disabled.

• First, i just open it with my mouse, we can see that the first and last items can't be highlighted
• Then, i open it with Arrow down, first item is highlighted, even if it's disabled
• Same with Arrow up and last item

Reproduction repository:

Here is where i have recorded the video :
https://codesandbox.io/s/snowy-cloud-t5zyw?file=/src/hooks/useSelect/basic-usage.js
It's a fork of Downshift examples with changes to reproduce on useSelect basic usage example.

Problem description:

Disabled elements should not be highlighted on menu opening with arrow keys

Suggested solution:

The reducer here : https://github.com/downshift-js/downshift/blob/master/src/hooks/useSelect/reducer.js#L42-L63 is using getHighlightedIndexOnOpen to know which item to highlight on menu opening.
But it returns 0 or items.length - 1 if it doesn't fit with initial, default and selectedItem values : https://github.com/downshift-js/downshift/blob/master/src/hooks/utils.js#L304

Maybe this return should be improved to use getNextNonDisabledIndex here : https://github.com/downshift-js/downshift/blob/master/src/utils.js#L368-L407 ?
As it's currently done with MenuKeyDownArrowDown/MenuKeyDownArrowUp and getNextWrappingIndex that use getNextNonDisabledIndex : https://github.com/downshift-js/downshift/blob/master/src/utils.js#L343-L355

Hope the problem is understood, let me know if it's not 🙂

[tobiasthorin]

I'm having this issue as well, exactly like you describe.

While it doesn't fix the highlighting issue, at least you can avoid the disabled item being selected by giving Downshift a state reducer that looks like this:

useSelect({
  stateReducer: (state, actionAndChanges) => {
    // If the item to be selected is disabled, don't select it.
    if (actionAndChanges.changes.selectedItem?.disabled) {
      return { ...actionAndChanges.changes, selectedItem: state.selectedItem };
    }

    return actionAndChanges.changes;
  }
})

This code snippet relies on having a disabled property on your items. If you don't, then you will have to figure out if the soon-to-be-selected item is disabled or not some other way.

[silviuaavram]

Duplicate of #1176. Will track it there.