calebthebrewer/gulp-selectors

/**
 * Removes all CSS declarations in the library which are unused.
 * This doesn't get anything with a secondary selector. Help my regex!
 *
 * @param file
 * @param classLibrary
 * @returns {*}
 */
module.exports =  function(file, classLibrary) {

    classLibrary.getUnused().forEach(function(selector) {
        var expression = new RegExp('[,?\\s*]\\.' + selector + '\\s*{[^}]*}', 'g');
        file = file.replace(expression, function(match) {
            if (match[0] !== ',') {
                //remove declaration
                return '';
            } else {
                //only remove selector
                var subExpression = new RegExp('[,?\\s*]\\.' + selector);
                return match.replace(subExpression, function() {
                    return '';
                });
            }
        });
    });

    return file;
};