inflight-barrier

One promise for multiple tasks in flight to avoid async duplication

Usage no npm install needed!

<script type="module">
  import inflightBarrier from 'https://cdn.skypack.dev/inflight-barrier';
</script>

README

inflight-barrier

One promise for multiple requests in flight to avoid async duplication

Usage

import createInflightBarrier from 'inflight-barrier'

const barrier = createInflightBarrier()

// some request that does some stuff
function req(key) {
  // key can be any value which can be used as a key in a Map
  return barrier(key, () => {
    // this is where you'd fetch the url or whatever
    return Promise.delay(100)
  })
}

// only assigns a single setTimeout
// when it dings, all thens get called with the same result.  (There's only
// one underlying promise.)
req('foo').then(…)
req('foo').then(…)
req('foo').then(…)
req('foo').then(…)

See Also