Await the last async

async function foo() {
    await a()
    await b()
}

async function a() {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log('a')
            resolve('a')
        }, 10)
    })
}

async function b() {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log('b')
            resolve('b')
        }, 10)
    })
}

void async function () {
    await foo()
    console.log('c')
}()