[BUG] 'ReferenceError: setImmediate is not defined' on the browser

[asyncmax]

Expected Behavior

DataLoader should gracefully fall back to setTimeout if setImmediate is not supported on the browser.

Current Behavior

It crashes with an error ReferenceError: setImmediate is not defined.

Possible Solution

dataloader/src/index.js

Line 242 in 249b2b9

setImmediate || setTimeout;

-    setImmediate || setTimeout;
+   typeof setImmediate === 'function' ?
+      setImmediate :
+      (fn => {setTimeout(fn, 0);});

This code also fixes a problem of calling setTimeout without a delay number when it falls back.
Sorry, I didn't create a PR as I am not familiar with the Flow typing that this project is based on.

[Discordius]

This appears to also be breaking my build.

[DoneDeal0]

Adding Yuzu's polyfill fixed the issue for me: https://github.com/YuzuJS/setImmediate/blob/master/setImmediate.js

On top of index.ts/js or at the top of your file(s) that use dataloader, just add:

import "setimmediate";

[nanto]

Since setImmediate is no longer on a standard track and latest major browsers don't implement it (IE 11 is no longer a "major browser"), I think it is better if we can run dataloader on browsers without setImmediate polyfill.

[saihaj]

#293