Delay

If the call is not awaited, execution continues:

// Schedule 'someFn' after 100ms
delay(someFn, 100);
// ...but execution continues here immediately

By default the delay period is before running the supplied function, but it can also be after:

// Runs 'someFn' immediately
await delay(someFn, { delay: "after", secs: 10 });
// ...but execution does not continue here until 10 seconds later

Or both:

// Waits 10seconds, and then runs `someFn`
await delay(someFn, { delay: "both", secs: 10 });
// ...and waits a further 10secs before continuing here

Compared to ‘sleep’

Flow.delay is very similar to sleep, but lets you schedule running a function after the sleep.

So instead of writing:

import { sleep } from "https://unpkg.com/ixfx/dist/flow.js"
await sleep(100); // Pause for 100ms
await someFn();   // Call and wait for someFn to run

You can write:

import { delay } from "https://unpkg.com/ixfx/dist/flow.js"
await delay(someFn, 100);

sleep is particularly elegant when you have multiple sleeps between code:

await doSomething();
await sleep(100);
await doSomethingElse();
await sleep(50);
await andAnotherThing();