.js

import { v, validate } from '.'

async function run() {
    const body = {
        uname: '  foo  ',
        pass1: 'secret',
        pass2: 'secret',
        nums: [1, 2, 3],
        users: [{ uname: 'foo' }, { uname: 'bar' }],
        a: { b: 42 },
    }

    const result = await validate(body, {
        // reach into objects
        a: {
            b: [v.isInteger()],
        },
        // verify each object in array and then transform the array
        users: [
            v.arrayOf({
                uname: [v.isString()],
            }),
            v.map(xs => xs.map(user => user.uname)),
        ],
        // verify each number in array and then sum the numbers
        nums: [
            v.arrayOf([v.isInteger()]),
            v.map(xs => xs.reduce((acc, n) => acc + n, 0)),
        ],
        uname: [v.tip('test'), v.map(s => s.trim())],
        pass1: [v.isString()],
    })

    // check against a previous validation result
    await validate(body, {
        pass2: [v.isString(), v.eq(result.pass1)],
    })

    // validated + transformed result is:
    //
    //     { a: { b: 42 },
    //       users: ['foo', 'bar'],
    //       nums: 6,
    //       uname: 'foo',
    //       pass1: 'secret' }

    return result
}
run().then(console.log, console.error)