loss of empty attribute value

[alexander-akait]

Reproducible example:

const parser = require('postcss-selector-parser');

const transform = (selectors) => {
  selectors.walk((selector) => {
    // do something with the selector
  });
};

const transformed = parser(transform).processSync('a[href=""]');

console.log(transformed);
// a[href]

[alexander-akait]

Also broken parsing [href="" i] (it is valid selector)