feat(Formatter): add space inside option

[sirreal]

WIP

Summary

Add formatting option to include spacing inside parentheses, square brackets, curly braces, and angle brackets.

For example, this input:

function id<TypeArg>(x: TypeArg): TypeArg {
	return x;
}
const arr = [1, 2, 3];
if (id(true)) {
	// …
}

Would be formatted as follows with a "space inside" option enabled:

function id< TypeArg > ( x: TypeArg ): TypeArg {
	return x;
}
const arr = [ 1, 2, 3 ];
if ( id( true ) ) {
	// …
}

See #2360 (comment).
Closes #4607 (eventually).

Test Plan

[ematipico]

@sirreal would you mind creating a task first? Or an umbrella issue?

This isn't something that we might be able to ship in one PR, there's a lot of stuff to take into account:

• CLI
• option names
• comments
• formatting strategies

[sirreal]

Sure, thanks. I've created #4607.

This PR really a placeholder and I have a number of questions of my own after spending just a bit of time on this 🙂

[codspeed-hq]

CodSpeed Performance Report

Merging #4605 will not alter performance

_{Comparing sirreal:add/space-around-format-option (19de599) with main (610d09d)}

Summary

✅ 95 untouched benchmarks

[antony]

I'd love to see this be slightly more configurable, though, as I find that spaces inside brackets actually reduces readability, for example:

[ 1, I, ., L ]
// vs
[1,I,.,L]

is much more readable

however:

someCall(foo(bar(baz)))
// vs
someCall( foo ( bar ( baz ) ) )

actually feels less readable.

I think in terms of accessibility, the square brackets thing is huge, but the round brackets part is contentious.

another rule we used to have is actually spaces after function names:

// to declare a function:
function foo (bar) {
  ...
}
// to call it
function foo(bar)

makes skimming over code much easier as you can easily see the difference between declaration and call

[ematipico]

@antony please open an RFC or an issue. For us, a PR isn't a place to debate/bikeshed possible configurations, it's mostly about discussing technical decisions.

I asked interested parties to create an RFC, but no-one has done that.