Bluebird finally & tap difference

bluebird-finally-tap.js

'use strict';

const Promise = require('bluebird'); // at least 3.3.5
const log = console.log.bind(console); // bind is safeguard for browser

Promise.resolve('value 1')
.tap(log) // value 1
.then(log)// value 1
.then(log)// undefined
.then(() => Promise.reject(new Error('reason 1')))
.tap(() => log('Never printed!'))
.finally(() => log('"finally" is called for rejection but not "tap"')) // "finally" is called for rejection but not "tap"
.catch(log) // [Error: reason 1]
.then(() => Promise.reject(new Error("reason 2")))
.finally(() => Promise.reject(new Error("reason 3")))
.catch(log) // [Error: reason 3]

/*
value 1
value 1
undefined
"finally" is called for rejection but not "tap"
[Error: reason 1]
[Error: reason 3]
*/