Hey there, let's dig into why your download-progress event isn't firing even though other auto-updater events (like checking-for-update, update-available, and update-downloaded) are working correctly. Here are practical troubleshooting steps and fixes:

1. Upgrade electron-updater to the Latest Stable Version #

Older versions of electron-updater had known bugs where the download-progress event failed to trigger properly, especially with the generic publish provider. Run this command to update:

npm install electron-updater@latest
# Or for Yarn users:
yarn add electron-updater@latest

Rebuild your app after updating and retest the update flow.

2. Verify Server Response Headers for the Update Package #

The download-progress event depends on your server returning a Content-Length header for the update file (your .dmg/.zip). Without this header, electron-updater can't calculate download progress, so it won't fire the event.

To check:

• Use your browser's dev tools (Network tab) to manually download the update file and inspect the response headers
• Ensure Content-Length is present and matches the actual file size

If the header is missing, configure your web server (Nginx, Apache, etc.) to include Content-Length for static files.

3. Add Detailed Logging to Diagnose Event Triggering #

Your current code only sends a static message when download-progress fires—add logging to confirm if the event is actually being triggered. Update your handler like this:

autoUpdater.on('download-progress', progressObj => {
  // Log progress details to your electron-log file
  log.info(`Download Progress: ${Math.round(progressObj.percent)}% | Transferred: ${progressObj.transferred} bytes | Total: ${progressObj.total} bytes`);
  // Send detailed progress to the renderer
  win.webContents.send('submitted-form', `Downloading update: ${Math.round(progressObj.percent)}% complete`);
});

Check your app's log file (on macOS, it’s at ~/Library/Logs/[Your App Name]/main.log):

• If log entries appear, the event is firing—your renderer might not handle the submitted-form message correctly
• If no logs appear, the event isn’t triggering at all, pointing to an electron-updater or server configuration issue

4. Test with a Larger Update Package #

If your update package is very small (a few KB), it might download so quickly that the download-progress event doesn’t have time to fire before completion. Try adding a dummy large file to your app bundle to create a bigger test update, then retest the flow.

5. Confirm Auto-Download is Enabled #

While your update-downloaded event fires (so this is unlikely), double-check auto-download isn’t disabled. Add this line before autoUpdater.checkForUpdates():

autoUpdater.autoDownload = true; // Default is true, but explicit confirmation helps

6. Check for Conflicting Event Handlers #

Make sure no other code is overriding or removing the download-progress listener. For example, accidental calls to autoUpdater.removeAllListeners('download-progress') would prevent your handler from firing.

内容的提问来源于stack exchange，提问作者yun