[Bug] 37 dev branch,. fails on electronSwitches

[sdetweil]

Environment

System Information

• SYSTEM: manufacturer: System manufacturer; model: System Product Name; virtual: false; MM: v2.37.0-develop
• OS: platform: linux; distro: Ubuntu; release: 22.04.5 LTS; arch: x64; kernel: 5.15.0-177-generic
• VERSIONS: electron: 42.1.0; used node: 24.15.0; installed node: 22.22.1; npm: 10.9.4; pm2: 5.4.3
• ENV: XDG_SESSION_TYPE: x11; MM_CONFIG_FILE: undefined
  WAYLAND_DISPLAY: undefined; DISPLAY: :0.0; ELECTRON_ENABLE_GPU: undefined
• RAM: total: 48076.70 MB; free: 40129.30 MB; used: 7947.40 MB
• OTHERS: uptime: 11076 minutes; timeZone: America/Chicago
  [2026-05-18 14:18:58.875] [LOG] [electron] Launching applic

Which start option are you using?

node --run start:x11

Are you using PM2?

No

Module

None

Have you tried disabling other modules?

• Yes
• No

Have you searched if someone else has already reported the issue on the forum or in the issues?

• Yes

What did you do?

Configuration

    electronSwitches: {
      "password-store": "basic",
      "js-flags": "--max-old-space-size=8192"
    },

<!-- Paste relevant code here -->

Steps to reproduce the issue:

What did you expect to happen?

has been working for 'years' (or maybe not working)

What actually happened?

I added the console.log elsw...

[2026-05-18 14:18:58.876] [LOG]   [electron] elsw { 'password-store': 'basic', 'js-flags': '--max-old-space-size=8192' }
[2026-05-18 14:18:58.877] [ERROR] [unknown] (node:725432) UnhandledPromiseRejectionWarning: TypeError: object is not iterable (cannot read property Symbol(Symbol.iterator))
    at createWindow (/home/sam/MagicMirror.2.36.dev/js/electron.js:49:39)

config.js

    electronSwitches: {
      "password-store": "basic",
      "js-flags": "--max-old-space-size=8192"
    },

from the electron doc , SOME switches are keyword/value

app.commandLine.appendSwitch('remote-debugging-port', '8315')
app.commandLine.appendSwitch('host-rules', 'MAP * 127.0.0.1')

so the config value cannot be flat array of single values.. ,, I think appendswitch of {'remote-debugging-port': '8315'} , would fail too

i'm guessing the old code didn't work either

        let electronSwitchesDefaults = ["autoplay-policy", "no-user-gesture-required"];
        app.commandLine.appendSwitch(...new Set(electronSwitchesDefaults, config.electronSwitches));

at least, the defaults were connected , "autoplay-policy":"no-user-gesture-required"

changing my switches to

    electronSwitches: [
      {"password-store": "basic"},
      {"js-flags": "--max-old-space-size=8192"}
    ],

doesn't produce an error on startup, but I don't know if the switches are correctly passed..

Additional comments

No response

Participation

• I am willing to submit a pull request for this change.

[KristjanESPERANTO]

Thanks Sam - yes, this is a real issue.

electronSwitches was broken since PR #2643 (the new Set(...) swallowed the user config). #4136 only got it working like the way the docs claimed - array of strings - but as you point out, that design can't express switches with values, since Electron wants appendSwitch(name, value).

I think the cleanest fix is to just switch to an object. I'll take a look in the next days.

[sdetweil]

I didn't see any electron examples of plain switch --foobar

but this heading lists some..
https://www.electronjs.org/docs/latest/api/command-line-switches#electron-cli-flags

does appendSwitch have an override for no value for the switch? or are these ONLY allowed on the commandline??

whats the difference between a switch and a flag? if they both can be done on the cli???

[KristjanESPERANTO]

I checked this locally with Electron.

appendSwitch does seem to support both forms:

app.commandLine.appendSwitch("no-sandbox");
app.commandLine.appendSwitch("js-flags", "--max-old-space-size=8192");

That gives me:

{"noSandbox":true,"jsFlags":"--max-old-space-size=8192"}

I also checked whether passing name=value as a single string would work:

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

That does not register js-flags; it registers the whole string as the switch name. So the current array-of-strings design really can't express switches with values.

On "switch" vs "flag": I'm not sure there is a strict distinction here. Electron seems to use both terms for command-line args like --name or --name=value.

So I still think an object form maps best to Electron's API:

electronSwitches: {
    "no-sandbox": true,
    "js-flags": "--max-old-space-size=8192"
}

I'll try to look into this soon more deeply and open a PR if it works out. Unless someone else wants to take a shot at it first :)

[sdetweil]

I don’t like this but, js arrays support dissimilar things

[
"no-sandbox”,
{ "js-flags": "--max-old-space-size=8192"}
]
And it’ll be a pain to support in mmm-config

So if the array element is a string,
Then use the single form append
Else if object not array,
use the dual form, object_key, object_value
Else error

Then you dont have any ambiguity over the object value fake ‘true’ in

"no-sandbox": true,

[KristjanESPERANTO]

Okay, keeping the array is also a good choice. I've created #4161 :)