https config cannot be asynchronous

[juliendargelos]

The https configuration requires a synchronous export from a module. But in some cases it would be useful to export a promise:

Using fs asynchronous functions

With fs callback functions (kind of ugly):

const fs = require('fs')

module.exports = Promise.all([
  new Promise((resolve, reject) => {
    fs.readFile(__dirname + '/server.cert', (error, cert) => error ? reject(error) : resolve(cert))
  }),
  new Promise((resolve, reject) => {
    fs.readFile(__dirname + '/server.key', (error, key) => error ? reject(error) : resolve(key))
  })
]).then(([cert, key]) => ({ cert, key, passphrase: '12345' }))

With fs experimental promises or fs-extra:

const fs = require('fs').promises // const fs = require('fs-extra')

module.exports = Promise.all([
  fs.readFile(__dirname + '/server.cert'),
  fs.readFile(__dirname + '/server.key')
]).then(([cert, key]) => ({ cert, key, passphrase: '12345' }))

Using devcert:

const devcert = require('devcert')

module.exports = (async () => ({
  ...(await devcert.certificateFor('localhost')),
  passphrase: '12345'
})()

Can be one-lined when passphrase is not needed:

module.exports = require('devcert').certificateFor('localhost')

Personally, I would prefer being able to pass an object to the https option, so asynchronous stuff can be handled by the user, outside live-server:

const liveServer = require('live-server')
const devcert = require('devcert')

;(async () => liveServer.start({
  // ...
  https: await devcert.certificateFor('localhost')
})()