How do I increase electron forge memory heap size?

Question

I have a template app made with electron forge, and when I try to execute the following code

const ARRAY_LENGTH = 1.1e8;
const randomArray = [];
for (let i = 0; i < ARRAY_LENGTH; i += 1) {
  randomArray.push(Math.random());
}

I believe I run out of memory with the following error:

<--- Last few GCs --->

[23850:0x7900000000]    16762 ms: Mark-sweep (reduce) 3622.1 (3706.7) -> 3478.0 (3562.6) MB, 1806.7 / 0.0 ms  (+ 0.5 ms in 1 steps since start of marking, biggest step 0.5 ms, walltime since start of marking 2717 ms) (average mu = 0.589, current mu = 0.60[23850:0x7900000000]    20404 ms: Mark-sweep (reduce) 3478.0 (3562.6) -> 3286.0 (3370.6) MB, 3640.7 / 0.0 ms  (average mu = 0.307, current mu = 0.000) last resort GC in old space requested


<--- JS stacktrace --->

I'm wondering how I increase the memory available to the process?

Note: tried adding preload script in forge.config.js as described here, using the following (to no avail, although the preload script does run):

// preload.ts
import { remote } from 'electron';

remote.app.commandLine.appendSwitch('js-flags', '--max-old-space-size=8192');