Asynchronous map function that await's returns Promise instead of value

问题

I have this code

async function addFiles(dir,tree) {
  return (await readDir(dir))
    .map(async (name) => {await readDir(dir); return name;})
}

but unfortunately, it just returns a bunch of promises, because there the async function in map is not waited upon. I'm wondering if there is any way to await the mapped function in the above code.

回答1:

try

async function addFiles(dir,tree) {
  const files = await readDir(dir)
  await Promise.all(files.map(async (name) => {await readDir(dir); return name;})
}

回答2:

If you're using bluebird you can use this cleaner, shorter syntax with Promise.map

async function addFiles(dir, tree) {
  const files = await readDir(dir);
  return Promise.map(files, async (name) => { await readDir(dir); return name; });
}

来源：https://stackoverflow.com/questions/36992590/asynchronous-map-function-that-awaits-returns-promise-instead-of-value