issue:
Per the spec, ~= with an empty value matches nothing. css-select matches a="" and values with leading, trailing or doubled spaces.

repro:

import { selectAll } from "css-select";
import { parseDocument } from "htmlparser2";
const doc = parseDocument('<i a=""></i><i a=" x"></i><i a="x "></i><i a="x  y"></i>');
console.log(selectAll('[a~=""]', doc).length); // 4

expected:
prints 0 (as Chrome, Firefox, Safari)

system:
css-select 7.0.0, Node 25.8.1
macOS 27.0, arm64