SOURCE

const showLight = ({color, delay} = {color: 'red', delay: 1000}) => {
    return new Promise(resolve => {
        console.log(color)
        const timer = setTimeout(resolve, delay)
    })
}

async function showLights(lights) {
    while(lights.length) {
        const curLight = lights.pop()
        await showLight(curLight)
        lights.unshift(curLight)
    }

    
    // await showLight()
    // await showLight({color: 'yellow', delay: 1000})
    // await showLight({color: 'green', delay: 1000})
    // showLights(lights)
}

showLights([{color: 'yellow', delay: 1000}, {color: 'green', delay: 1000}])