Node.before() inserts after if the new node is already a sibling

Test case:

const postcss = require("postcss");

const root = postcss.parse("@foo; @bar; @baz");
const foo = root.nodes[0];
const baz = root.nodes[2];
baz.before(foo);
root.toString(); // expected: "@bar; @foo; @baz"
                 // actually: "@bar; @baz; @foo"

It looks like the index calculation gets stale once the new node is removed from its original location.

[ai]

Each method first checks if the node exists and removes it, if needed. I think this might be a breaking change for some plugins.

Yes, it could be dangerous.

It is better to call remove() in plugin.

[ai]

Sorry, I need to ask a help with research and PR.

I am spending all my free resources helping people affected by war.