Wrapping a unit test in a transaction for easy cleanup with Knex.js

knex.js

#!/usr/bin/node
const Promise = require('bluebird')
const config  = require('./config.json')
const knex    = require('./lib/knex')(config.database).connection()


const mock = () => ({ user_id: Math.floor(Math.random() * 999) + 1, payload_type: 'foo', attributes: JSON.stringify({}) })


const before = (t) => {
    console.log('before')
    const tmp = {}
    const p = new Promise( (resolve, reject) => tmp.resolve = resolve )
    knex.transaction( tx => { t.tx = tx; tmp.resolve() } ).catch( () => {} )
    return p
}

const test = async (t) => {
    console.log('test')
    let m1 = mock(), m2 = mock()
    await t.tx('notifications').insert(m1)
    await t.tx('notifications').insert(m2)
}

const after = (t) => {
    console.log('after')
//    return t.tx.commit()
    return t.tx.rollback()
}


let t = {}
             before(t)
.then( () => test(t)  )
.then( () => after(t) )
.catch( e => console.log(`e: ${e}`) )

catch(() => {}); //why things not working if remove this line?

knex turns the rollback into an exception which then fails the ava test