transform-fragments.js

const onlySpace = /^\s+$/g;
const spaceBetforeTagClose = /\s+(>)/g;
const spaceBetweenTags = /(>)\s+(<)/g;
const spaceBetweenAttrs = /(["'\w])(?!\s*>)\s+/g;
const openEnded = /(?:[^="'\w])?(["'\w])\s*$/g;

export function transformHTMLFragment(data) {
    // if the chunk is only space, collapse and return it
    if (data.match(onlySpace)) {
        return data.replace(onlySpace, " ");
    }

    // remove space before tag close
    data = data.replace(spaceBetforeTagClose, "$1");

    // remove space between tags
    data = data.replace(spaceBetweenTags, "$1$2");

    // remove space between attributes
    data = data.replace(spaceBetweenAttrs, "$1 ");

    if (data.match(openEnded)) {
        return data.trimStart();
    }

    return data.trim();
}

const newlines = /\n/g;
const separators = /\s*([\{\};])\s*/g;
const lastProp = /;\s*(\})/g;
const extraSpaces = /\s\s+/g;
const endingSpaces = / ?\s+$/g;

export function transformCSSFragment(data) {
    // newlines
    data = data.replace(newlines, "");

    // Remove extra space, but not too much
    data = data.replace(separators, "$1");

    // Remove semicolons followed by property list end
    data = data.replace(lastProp, "$1");

    // space might be between property values or between selectors
    data = data.replace(endingSpaces, " ");

    return data.replace(extraSpaces, " ");
}