Add middle attributes sorting

[SkyaTura]

TODO

• Explain this PR

Original post

## Reason for this PR

Every time this code is saved it gets a different result:

<template lang="pug">
Foo(c b a d i f g h e l n)
</template>

Expected result

<template lang="pug">
Foo(a b c d e f g h i l n)
</template>

[SkyaTura]

I've accidentally formatted things that I shouldn't on a formatter library :P

Going to fix it right now!

[Shinigami92]

1. Please use draft PRs
2. Please request me as a reviewer if you are done

🙂

[Shinigami92]

Please add a prettier config to the issue descriptions

Currently I would expect that nothing would get sorted cause the default would be taken

Also please note that the sorting isn't sorting in an alphabetical order in any way

[SkyaTura]

So, I'm thinking and experimenting things for long hours now, but I can't find an answer.

What have I done since my first changes:

• In fact, this formatter had nothing to do with "middle attributes", so I've added a new option pugSortAttributes = 'as-is' | 'asc' | 'desc'. This could be reverted if you think it shouldn't exist.
• Added more test cases, with different middle attribute sorting options.

What I cannot understand is, why on earth compare 3 and compare 6 are failing.

This is the main problem, which I though I was solving. I kinda only refactored some code that was already working. 🤦🏻

[Shinigami92]

Can you rename the PR title? :)

And also you should merge master into your PR branch

[Shinigami92]

@SkyaTura Looking at the tests, it seems that your sort is not stable 🤔

[SkyaTura]

Yes, but I don't know why. My knowledge is limited here, because I though it should work correctly.

I'll study more about the sort method to understand what is going on, over this weekend, ( the last couple days have been busy for me :x )

[lehni]

Could it be the cases where the compare function returns 0 that leads to unstable sort?

Node's sort() wasn't stable up to about Node 11 or so.

Some bits about this:

https://bugs.chromium.org/p/v8/issues/detail?id=90
nodejs/node#29446 (comment)
https://medium.com/@fsufitch/is-javascript-array-sort-stable-46b90822543f

I would try a stable sort() method next, e.g.:

function stableSort(
  array,
  compare = (a, b) => a < b ? -1 : a > b ? 1 : 0
 ) {
  const entries = array.map((value, index) => [value, index]);
  entries.sort((a, b) => {
    const order = compare(a[0], b[0]);
    // When order is 0, sort by index to make the sort stable:
    return order != 0 ? order : a[1] - b[1];
  });
  return entries.map(([value]) => value);
}

Note that this doesn't modify array, it returns a sorted copy.

[SkyaTura]

Finally!!! My logic wasn't wrong after all 😅

Thank you a lot @lehni . This stableSort worked as a chamr.

[Shinigami92]

@SkyaTura @lehni Check out my newly added contributing.md 😃
Maybe it could help 🙂

[lehni]

@SkyaTura happy to hear that this helped! I was struggling with this situation a while back on Node also, it can be so confusing.

[Shinigami92]

Not quite sure, but isn't it : T[] as return type?

[SkyaTura]

To be honest, I'm new to TypeScript, I didn't knew how to properly type the method @lehni suggested.

Could you help me with this one?

It took a while to understand hahah

[Shinigami92]

Ah okay, I can checkout your branch at evening and then suggest some types