index.js•1.03 kB
/*! run-parallel. MIT License. Feross Aboukhadijeh <https://feross.org/opensource> */
module.exports = runParallel
const queueMicrotask = require('queue-microtask')
function runParallel (tasks, cb) {
let results, pending, keys
let isSync = true
if (Array.isArray(tasks)) {
results = []
pending = tasks.length
} else {
keys = Object.keys(tasks)
results = {}
pending = keys.length
}
function done (err) {
function end () {
if (cb) cb(err, results)
cb = null
}
if (isSync) queueMicrotask(end)
else end()
}
function each (i, err, result) {
results[i] = result
if (--pending === 0 || err) {
done(err)
}
}
if (!pending) {
// empty
done(null)
} else if (keys) {
// object
keys.forEach(function (key) {
tasks[key](function (err, result) { each(key, err, result) })
})
} else {
// array
tasks.forEach(function (task, i) {
task(function (err, result) { each(i, err, result) })
})
}
isSync = false
}