function loadScript(src, callback) {

const cb = callback || (() => {})

const $script = document.createElement('script')

$script.src = src

$script.id = src

document.body.appendChild($script)

const onEnd = 'onload' in $script ? stdOnEnd : ieOnEnd

onEnd($script)

function stdOnEnd(script) {

script.onload = () => {

this.onerror = this.onload = null

cb(null, script)

}

script.onerror = () => {

this.onerror = this.onload = null

cb(new Error(`Failed to load ${src}`), script)

}

}

function ieOnEnd(script) {

script.onreadystatechange = () => {

if (this.readyState !== 'complete' && this.readyState !== 'loaded') return

this.onreadystatechange = null

cb(null, script)

}

}

}

export default loadScript