App entrypoint fails to load for ESM app if arm64 and x64 apps don't match

[bendemboski]

If have an app whose main process is implemented as ES modules, and when I add a native dependency and don't merge the ASARs, the app fails to run with:

Uncaught Exception:
Error [ERR_REQUIRE_ESM]: require() of ES Module /private/var/folders/x5/lg2888612qx6k46g8t0b3llm0000gn/T/AppTranslocation/012E8191-C14B-424C-A98A-B6E43D98B159/d/Rowan Patents.app/Contents/Resources/app-arm64.asar/src/index.mjs not supported.
Instead change the require of /private/var/folders/x5/lg2888612qx6k46g8t0b3llm0000gn/T/AppTranslocation/012E8191-C14B-424C-A98A-B6E43D98B159/d/Rowan Patents.app/Contents/Resources/app-arm64.asar/src/index.mjs to a dynamic import() which is available in all CommonJS modules.
at l._load (node:electron/js2c/asar_bundle:2:13642)
at Object.<anonymous> (/private/var/folders/x5/lg2888612qx6k46g8t0b3llm0000gn/T/AppTranslocation/012E8191-C14B-424C-A98A-B6E43D98B159/d/Rowan Patents.app/Contents/Resources/app.asar/index.js:27:1)
at l._load (node:electron/js2c/asar_bundle:2:13642)
at node:electron/js2c/browser_init:2:120247
at node:electron/js2c/browser_init:2:120456
at node:electron/js2c/browser_init:2:120460
at l._load (node:electron/js2c/asar_bundle:2:13642)

I have worked around it using patch-package and replacing has-asar.js with a has-asar.mjs that looks like

import { app } from 'electron';
import path from 'path';

if (process.arch === 'arm64') {
  setPaths('arm64');
} else {
  setPaths('x64');
}

function setPaths(platform) {
  // This should return the full path, ending in something like
  // Notion.app/Contents/Resources/app.asar
  const appPath = app.getAppPath();
  const asarFile = `app-${platform}.asar`;

  // Maybe we'll handle this in Electron one day
  if (path.basename(appPath) === 'app.asar') {
    const platformAppPath = path.join(path.dirname(appPath), asarFile);

    // This is an undocumented API. It exists.
    app.setAppPath(platformAppPath);
  }

  process._archPath = `../${asarFile}`;
}

await import(`${process._archPath}/src/index.mjs`);

However, I'm not sure how to turn this into a general purpose solution because:

1. I hard-coded the path to my application's entry point (src/index.mjs) and I'm not sure a good way to determine it dynamically.
2. I'm not sure what process._archPath should actually be in this case?

[erickzhao]

Hey @bendemboski, I was taking a look at this today and it seems like the repro case happens whenever the x64 and arm64 ASARs diverge.

Converting the asar.js shim into its ESM equivalent indeed seems to fix the problem on my end.

Don't have time to put up a PR today but this seems to work according to my local testing.

// has-asar.mts
import { app } from 'electron';
import { createRequire } from 'node:module';
import path from 'node:path';

if (process.arch === 'arm64') {
  await setPaths('arm64');
} else {
  await setPaths('x64');
}

async function setPaths(platform: string) {
  // This should return the full path, ending in something like
  // Notion.app/Contents/Resources/app.asar
  const appPath = app.getAppPath();
  const asarFile = `app-${platform}.asar`;

  // Maybe we'll handle this in Electron one day
  if (path.basename(appPath) === 'app.asar') {
    const platformAppPath = path.join(path.dirname(appPath), asarFile);

    // This is an undocumented API. It exists.
    app.setAppPath(platformAppPath);
  }

  const require = createRequire(import.meta.url);
  process._archPath = require.resolve(`../${asarFile}`);
  await import(process._archPath);
}