perf: switch to empathic for config resolution

[43081j]

We can get an easy performance bump by using empathic for config resolution (traversal up the fs tree).

We shouldn't be traversing often but this is still a gain, even if small in mocha's case. We're also moving an increasing number of tools to use empathic, so this will de-dupe well over time as it allows us to consolidate many packages across the ecosystem into using just this one.

PR ready to go if you want it 👍

[JoshuaKGoldberg]

empathic looks good, but it only picked up dependencies over the last month or two, right? It strikes me as a pretty early stage improvement and a bit of a risk still. I'd feel more comfortable waiting for a few months and until a few large+stable packages use it.

[43081j]

the downloads and npm stats are a little misleading

there's quite a few in flight PRs from the last few months, and unreleased versions, etc

we're likely to land it in storybook, for example. and probably anywhere my own fd-package-json package is used (as it is faster)

happy to wait though, but the code isn't really questionable given how simple of a utility it is. i suppose age only tells you the maintainer will stick around, and we already know that

[JoshuaKGoldberg]

My big focus on age is to give projects a chance to have edge case bugs reported. It's really more "how many cases have been tried?" than raw age or download count. I don't think we need to wait for something >= Mocha's size adopts it (if everybody did that strategy, nothing would ever happen!) but just seeing some non-trivial projects keep it around for a while would inspire confidence.

👍 from me on this once a few other projects with many users have had it for a few months.

[mark-wiemer]

Related to #5346

[voxpelli]

Swapping a ≈163221k weekly downloads with 5406 dependents for a ≈32k weekly downloads with 10 dependents (and picking up steam very recently) is something that requires quite a bit of consideration and justification.

I'm not sure this is the kind of swap that mocha should be spearheading – there are other more cutting edge modules out there that can take the hit first.

There's also a lighter alternative of find-up itself that should also be considered: https://www.npmjs.com/package/find-up-simple

[43081j]

requires quite a bit of consideration and justification

indeed it does. the justification is solved and easy: empathic is lighter and faster than the one we use now, and alternatives (like the one you mentioned). we're only really blocked by trust here - maintainers being able to trust that the package is bug free and does what it says it does (which is fair enough).

mocha isn't spearheading it, as many, many other packages will be making this same migration long before mocha. this is just to track that one day we may want to do it

we can wait a little until more of these projects have it in the wild before moving (and should).

[JoshuaKGoldberg]

I'm going to go ahead and mark this as a duplicate of #5346, since that one is a bit older. We can continue discussion there. 👍