feat(formatter): add expand

[ematipico]

Summary

This PR closes #4370

I added a new option called expand. It was suggested expandLiterals, but it doesn't seem very beginner-friendly:

• it's not very clear what "literal" means to a beginner
• strings, booleans and numbers are also literals, so it could be confusing

However, feel free to suggest some other name.

Also, package.json is always expanded, unless the user decides to change the defaults.

Test Plan

I added new tests

[codspeed-hq]

CodSpeed Performance Report

Merging #4819 will not alter performance

_{Comparing feat/json-formatting (53a9018) with next (17cf8f7)}

Summary

✅ 97 untouched benchmarks

[arendjr]

I do admit I’m not really happy with the naming. My first thought was the option was something to configure lists of something to expand (kinda like allowLists), and I only understood what it actually meant after reading the description. But maybe that’s just me 😅

But even after reading it, I understood it would apply to arrays, but I was still surprised it applied to objects too. I don’t think I’ve ever seen objects called lists in any terminology before, so this doesn’t really make sense to me.

I actually think there’s less confusion with expandLiterals, because even though the term literals applies to primitives too, I don’t think anyone is surprised it doesn’t expand literals that cannot be expanded.

I also think “literal” is not really a beginner-unfriendly term. It’s surely better than calling things incorrectly to avoid the actual correct words.

I also considered expandObjects. At least there’s the precedent that JavaScript considers arrays to be objects, but I still prefer expandLiterals overall, since both “object literal” and “array literal” are commonly accepted in JavaScript terminology and expandObjects may just introduce confusion in the opposite direction that expandLists does.

[ematipico]

What do you think of just expand? We can document it by saying:

• that Biome will try to format the document by using less width as possible;
• or, that Biome will try to format lists like arrays and objects on multiple lines

[arendjr]

Hm, yeah. Given it’s only for JSON, where there aren’t many other explanations possible, I think that could work:)