login_ext.js

login_ext.js

const suppose = require('suppose')
    , fs = require('fs');

suppose('npm', ['login', '--registry=http://npm.sencha.com', '--scope=@extjs'], {debug: fs.createWriteStream(__dirname+'/debug.txt')})
    .when('Username: ' ).respond('{{YOUR_EMAIL}}\n')
    .when('Password: ' ).respond('{{YOUR_PASSWORD}}\n')
    .when('Email: (this IS public) ' ).respond('mymislife@gmail.com\n')
    .on('error', (err)=>{
        console.error(err.message);
    })
    .end(()=>{
        const packageFile = '/tmp/awesome/package.json';
        fs.readFile(packageFile, ()=>{
            console.log("login success");
        })
    });

Step1: npm i suppose
Step2: Replace {{YOUR_EMAIL}} with your email
Step3: Replace {{YOUR_PASSWORD}} with your password
Step4: node login_ext.js