Same as slugify.js but using underscore

underscoredSlug.js

// Same as slugify.js but using underscore

// Ex: "Anões de Jardim Botânico" will become "anoes_de_jardim_botanico"

function underscoredSlug (text) {
    const a = 'àáãäâèéëêìíïîòóöõôùúüûñçßÿœæŕśńṕẃǵǹḿǘẍźḧ·/-,:;';
    const b = 'aaaaaeeeeiiiiooooouuuuncsyoarsnpwgnmuxzh______';
    const p = new RegExp(a.split('').join('|'), 'g');

    return text.toString().toLowerCase()
        .replace(/\s+/g, '_')           // Replace spaces with _
        .replace(p, c =>
            b.charAt(a.indexOf(c)))     // Replace special chars
        .replace(/&/g, '_and_')         // Replace & with 'and'
        .replace(/[^\w\-]+/g, '')       // Remove all non-word chars
        .replace(/\_\_+/g, '_')         // Replace multiple - with single -
        .replace(/^_+/, '')             // Trim - from start of text
        .replace(/_+$/, '')             // Trim - from end of text
}