Dependency-Based Parallelization
For operations with partial dependencies, use better-all to maximize parallelism. It automatically starts each task at the earliest possible moment.
Incorrect (profile waits for config unnecessarily):
const [user, config] = await Promise.all([
fetchUser(),
fetchConfig()
])
const profile = await fetchProfile(user.id)Correct (config and profile run in parallel):
import { all } from 'better-all'
const { user, config, profile } = await all({
async user() { return fetchUser() },
async config() { return fetchConfig() },
async profile() {
return fetchProfile((await this.$.user).id)
}
})Alternative without extra dependencies:
We can also create all the promises first, and do Promise.all() at the end.
const userPromise = fetchUser()
const profilePromise = userPromise.then(user => fetchProfile(user.id))
const [user, config, profile] = await Promise.all([
userPromise,
fetchConfig(),
profilePromise
])Reference: https://github.com/shuding/better-all