Allow updating mac version running inside Rosetta to native ARM (#5901)

* Allow updating mac version running inside Rosetta to native ARM version if available
Co-authored-by: Dave Jeffery <dave@davejeffery.com>

packages/electron-updater/package.json

@@ -13,6 +13,7 @@
   ],
   "dependencies": {
     "@types/semver": "^7.3.6",
+    "builder-util": "workspace:*",
     "builder-util-runtime": "workspace:*",
     "fs-extra": "^10.0.0",
     "js-yaml": "^4.1.0",

packages/electron-updater/src/MacUpdater.ts

@@ -8,6 +8,7 @@ import { AppUpdater, DownloadUpdateOptions } from "./AppUpdater"
 import { ResolvedUpdateFileInfo } from "./main"
 import { findFile } from "./providers/Provider"
 import AutoUpdater = Electron.AutoUpdater
+import { spawn } from "builder-util"
 
 export class MacUpdater extends AppUpdater {
   private readonly nativeUpdater: AutoUpdater = require("electron").autoUpdater
@@ -26,13 +27,23 @@ export class MacUpdater extends AppUpdater {
     })
   }
 
-  protected doDownloadUpdate(downloadUpdateOptions: DownloadUpdateOptions): Promise<Array<string>> {
+  protected async doDownloadUpdate(downloadUpdateOptions: DownloadUpdateOptions): Promise<Array<string>> {
     let files = downloadUpdateOptions.updateInfoAndProvider.provider.resolveFiles(downloadUpdateOptions.updateInfoAndProvider.info)
 
+    // Detect if we are running inside Rosetta emulation
+    const sysctlRosettaInfoKey = "sysctl.proc_translated"
+    let isRosetta: boolean
+    try {
+      const results = await spawn(`sysctl`, [sysctlRosettaInfoKey])
+      isRosetta = results?.toString()?.includes(`${sysctlRosettaInfoKey}: 1`)
+    } catch (e) {
+      this._logger.info(`sysctl shell command to check for macOS Rosetta environment failed: ${e}`)
+    }
+
     // Allow arm64 macs to install universal or rosetta2(x64) - https://github.com/electron-userland/electron-builder/pull/5524
     const isArm64 = (file: ResolvedUpdateFileInfo) => file.url.pathname.includes("arm64")
     if (files.some(isArm64)) {
-      files = files.filter(file => (process.arch === "arm64") === isArm64(file))
+      files = files.filter(file => (process.arch === "arm64" || isRosetta) === isArm64(file))
     }
 
     const zipFileInfo = findFile(files, "zip", ["pkg", "dmg"])