wpapi.js Get or Create Tag example

wpapi_test.js

const api = require('wpapi');
const wp = new api({
    endpoint: 'https://wordpress.domain/wp-json',
    username: 'admin',
    password: 'admin'
});

var tags = ['a','b','c'];
var getOrCreateTags =  tags.map(tag => {
    return wp.tags().slug(tag)
        .then(r => {
            return r.length ? r[0]: wp.tags().create({name: tag, slug: tag});
        });
});
Promise.all(getOrCreateTag).then(tagList => console.log(tagList)).catch(e => console.error(e));