feat(minifier): simplify destructuring array assigment

[armano2]

simplify destructuring array assignment pattern

var [a] = [1] -> var a = 1
var [, [c]] = [2, [3]] -> var [] = 2, c = 3

use cases in a wild:

• https://github.com/oracle/bots-node-sdk/blob/ce1aa5ffff53ae9e988a799bd90a3e6ddbbf1611/bin/lib/spawn.js#L20
• https://github.com/Leask/Starlink-Signal-Status/blob/59c01b306ed028da0d8986e737e84146202159fc/lib/slss.mjs#L29
• https://github.com/search?q=%22%2C+err%5D+%3D+%5B%22+language%3AJavaScript+&type=code

[codspeed-hq]

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing armano2:fix/inline-statements (21d1b2d) with main (645c3f0)¹}

Summary

✅ 38 untouched benchmarks
⏩ 7 skipped benchmarks²

Footnotes

1. No successful run was found on main (62a00e5) during the generation of this report, so 645c3f0 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

2. 7 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[armano2]

ok, all changes applied, and it seem to be working fine

[armano2]

q: what do you think about not processing vars if there is more than one non literal value?

// in this case only one variable will be created and we could create it only if its not first
decl.kind.is_var() &&
init_expr.elements.iter().filter(|elem| !elem.is_literal_value(false, ctx)).count() > 1

or even do not do that if there is any non literal

// in this case we never create variables
decl.kind.is_var() &&
init_expr.elements.iter().any(|elem| !elem.is_literal_value(false, ctx))

that would let us handle all cases where we extensively create additional variables for vars

---

this solves issues like:

var [a, b] = [1, 2], [a, b] = [b, a] // in
var a = 2, b = 1 // new
var a = 1, _ = 2, _2 = a, a = _, b = _2 // old

var [a, b] = [!d, !a] // in - out
var _ = !d, _2 = !a, a = _, b = _2 // old

var [a, b] = [b, a], [a, b] = [b, a] // in - out
var _3 = b, _4 = a, a = _3, b = _4, _ = b, _2 = a, a = _, b = _2 // old

[armano2]

maybe we should extract this to something more generic

ideally we would want to resolve it based on nodeId by comparing sub-tree, but that's currently not supported

this produces better output than creating intermediate variables that would otherwise could never be in-lined