Create a lint rule that enforces appropriate usage of `Box`

[khiga8]

Problem statement

Primer React provides a couple of low-level utility components such as <Box>, <Text>, and <Heading>.

In particular, <Box> seems to be used in all sorts of ways, outside of what the doc describes:

basic wrapper component for most layout related needs.

For example, there's <Box as="h1">, <Box as="button">, when people could be rendering <Heading> or <h1> , or <Button> instead. Box usage outside of "wrapper-y" elements (e.g. div, section) feel like code smells.

There is an opportunity to create a linter that suggests a more appropriate element or component based on the as prop.

This isn't directly tied to accessibility, but components being used in a predictable manner is important.

<Box> rendered without sx are unnecessarily verbose and might as well just be semantic HTML elements. This will not only improve readability, but it would also apparently improve performance.

Related slack thread

Acceptance criteria

• Propose a lint rule that encourages appropriate usage of Box and/or auto-fixes it.
• Incorporate auto-fix.

[lesliecdubs]

Thanks for the suggestion @khiga8! This seems like a good idea for a component like Box, but may be tricky to implement more broadly since as is sometimes used properly to enforce better semantics. We'll try to take a look at this at some point for Box if nothing else.

[khiga8]

Another thing that I noticed is that there's a ton of usage of Box like:

<Box as="li"></Box>

when one could simply render <li>. These could probably be auto-fixed to use HTML elements.

It appears this serves no utility, makes code harder to read, and additionally contributes to performance issues.

Related slack thread

[khiga8]

Additional questions around validity of <Heading> and <Text>.

[khiga8]

@langermank brought up that there's an opportunity to flag migration from Box to the new Stack.

So far, there's quite a few "practices" we can enforce with Box which I'll note for now:

• <Box> without sx usage should just be semantic HTML elements… this seems autofixable.
• <Box as=> set to anything interactive or with alternate Primer components shouldn’t use Box .. they are code smells
  *<Box sx={ display: 'flex'> is a candidate for Stack. These might be autofixable too, depending on what other props are present.

These probably should be separate rules.