💅 a11y/noNoninteractiveTabindex incorrectly labels treegrid child roles as non-interactive

[drwpow]

Environment information

N/A

Rule name

lint/a11y/noNoninteractiveTabindex

Playground link

https://biomejs.dev/playground/?code=ZQB4AHAAbwByAHQAIABmAHUAbgBjAHQAaQBvAG4AIABUAHIAZQBlAEcAcgBpAGQAKAApACAAewAKACAAIAByAGUAdAB1AHIAbgAgACgACgAgACAAIAAgADwAZABpAHYAIAByAG8AbABlAD0AIgB0AHIAZQBlAGcAcgBpAGQAIgAgAGEAcgBpAGEALQBhAGMAdABpAHYAZQBkAGUAcwBjAGUAbgBkAGUAbgB0AD0AIgBjAGUAbABsAC0AMQAtADIAIgA%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%2BAAoAIAAgACAAIAAgACAAIAAgACAAIAA8AGQAaQB2ACAAaQBkAD0AIgBjAG8AbAAtADMAIgAgAHIAbwBsAGUAPQAiAGMAbwBsAHUAbQBuAGgAZQBhAGQAZQByACIAIAB0AGEAYgBJAG4AZABlAHgAPQB7ADAAfQA%2BAEMAbwBsAHUAbQBuACAAMwA8AC8AZABpAHYAPgAKACAAIAAgACAAIAAgACAAIAA8AC8AZABpAHYAPgAKACAAIAAgACAAIAAgADwALwBkAGkAdgA%2BAAoAIAAgACAAIAAgACAAPABkAGkAdgAgAHIAbwBsAGUAPQAiAHIAbwB3AGcAcgBvAHUAcAAiACAAdABhAGIASQBuAGQAZQB4AD0AIgAwACIAIABhAHIAaQBhAC0AZQB4AHAAYQBuAGQAZQBkAD0AIgBmAGEAbABzAGUAIgA%2BAAoAIAAgACAAIAAgACAAIAAgADwAZABpAHYAIAByAG8AbABlAD0AIgByAG8AdwAiAD4ACgAgACAAIAAgACAAIAAgACAAIAAgADwAZABpAHYAIABpAGQAPQAiAGMAZQBsAGwALQAxAC0AMQAiACAAcgBvAGwAZQA9ACIAZwByAGkAZABjAGUAbABsACIAIAB0AGEAYgBJAG4AZABlAHgAPQB7ADAAfQA%2BAEEAPAAvAGQAaQB2AD4ACgAgACAAIAAgACAAIAAgACAAIAAgADwAZABpAHYAIABpAGQAPQAiAGMAZQBsAGwALQAxAC0AMgAiACAAcgBvAGwAZQA9ACIAZwByAGkAZABjAGUAbABsACIAIAB0AGEAYgBJAG4AZABlAHgAPQB7ADAAfQA%2BAEIAPAAvAGQAaQB2AD4ACgAgACAAIAAgACAAIAAgACAAIAAgADwAZABpAHYAIABpAGQAPQAiAGMAZQBsAGwALQAxAC0AMwAiACAAcgBvAGwAZQA9ACIAZwByAGkAZABjAGUAbABsACIAIAB0AGEAYgBJAG4AZABlAHgAPQB7ADAAfQA%2BAEMAPAAvAGQAaQB2AD4ACgAgACAAIAAgACAAIAAgACAAPAAvAGQAaQB2AD4ACgAgACAAIAAgACAAIAA8AC8AZABpAHYAPgAKACAAIAAgACAAPAAvAGQAaQB2AD4ACgAgACAAKQA7AAoAfQA%3D

Expected result

Both treegrid and grid are described to work like spreadsheets on the web, where data can be edited and individual cells can be focused within and navigated using arrow keys.

Treegrid takes it one step further and allows expanding/collapsing of rows and columns like a tree.

So when trying to implement focus behavior, this throws an error when it shouldn’t:

// The HTML element div is non-interactive. Do not use tabIndex. (❌ Incorrect)
<div role="gridcell" tabIndex={0}>
                     ~~~~~~~~~~~~

This conflicts with the recommended behavior of treegrid children:

Right Arrow
If focus is on a collapsed row, expand the row. …

In other words, a gridcell MUST be focusable when inside a treegrid if it’s expandable (via tabIndex), and also MUST be able to receive other keyboard commands.

lint/a11y/noNoninteractiveTabindex is correct in other instances, so it seems this is only a problem with grid and treegrid children.

Other notes

• The useSemanticElements rule does apply to this example but is irrelevant; noNoninteractiveTabindex still raises the same errors
• Worth noting that, yes, by default many gridcells (and related roles) aren’t interactive, this issue is in certain scenarios they ARE REQUIRED to be
• The “roving tabindex” approach is optional here (where only the focusable element receives tabIndex={0} and everything else gets tabIndex={-1}), but also doesn’t affect the outcome

Code of Conduct

• I agree to follow Biome's Code of Conduct

[drwpow]

I’d be open to raising a PR, but wanted to discuss first whether or not it would be sufficient to remove gridcell (and friends—row, rowgroup, etc.) from the “always non-interactive” list.

I’m inclined to do so because looking at the base grid role docs, we see keyboard interactions suggested even for native <table> elements. This leads me to believe that even though the base elements aren’t focusable using browser defaults, they are still recommended to be in many usecases. Therefore tabIndex shouldn’t be discouraged.

However, if we wanted to take a more complex approach, where gridcell and friends are only interactive under certain conditions (e.g. only if a child of treegrid), I’d feel less confident opening a PR until we defined that criteria (and whether or not we could lint that if the components were broken up). Either way, open to thoughts!