Bluebird's promise map vs all difference

bluebird-map-vs-all.js

const Promise = require('bluebird');

const list = [300, 500, 400]

const getMapper = name =>
    ms => Promise.delay(ms).then(() => console.log(`${name}: ${ms}ms done in ${Date.now() - start}`));

const start = Date.now();

Promise.map(list, getMapper('map, infinity concurrency'));
Promise.map(list, getMapper('map, 1 concurrent'), {concurrency: 1});
Promise.all(list.map(getMapper('all')));

/* Sample output:
map, infinity concurrency: 300ms done in 309
map, 1 concurrent: 300ms done in 311
all: 300ms done in 312
map, infinity concurrency: 400ms done in 407
all: 400ms done in 407
map, infinity concurrency: 500ms done in 506
all: 500ms done in 506
map, 1 concurrent: 400ms done in 713
map, 1 concurrent: 500ms done in 1215
*/