The error `this.emit is not a function` has been raised while local storage has changed from other windows.

[vrtmrz]

Issue

Hi, team! I am always thankful to you for this grateful and excellent database!

I noticed that the error that I wrote in the title became shown on the browser. (It happens both with using pouchdb-browser and custom build from the core and some required plugins.). After I checked some behaviour and realise a concern, therefore I made a patch.
The reference to this looks has been captured in the function at packages/node_modules/pouchdb-utils/src/changesHandler.js.

I made the patch and tested it, and looks like works fine.

Would you mind if I make make a pull request?

Info

• Environment: Browser
• Platform: Chrome
• Adapter: idb
• Server: N/A

Reproduce

1. Open two windows of pouchdb.com
2. Open devTools in both windows. perform localStorage.setItem("Hello", World")
3. The error appears in the opposite window.

[steodor]

+1, we found this issue as well and came up with this exact same bugfix. We are currently monkey-patching the index.js and index-browser.js files in production so a pull request and official fix would be more than welcome. Thanks!

[vrtmrz]

I am relieved to hear that I am not the only one.

I made a pull request, hope it will be reviewed and processed, and PouchDB becomes perfect again!

[mbret]

Can confirm the issue, it broke my synchronization as well.

[ishaiavrahami]

Hi I’m also getting this error. Is there a solution for this?

[KorbinianKuhn]

We implemented a temporary fix while the Pull-Request is pending. Maybe it is useful for some of you:

postinstall.js

const { readFileSync, writeFileSync } = require('fs');
const { join } = require('path');

console.warn('Run PouchDB postinstall script to fix issue: https://github.com/pouchdb/pouchdb/issues/8581');

const filepath = join(__dirname, 'node_modules/pouchdb-browser/lib/index.es.js');

const content = readFileSync(filepath, 'utf-8');

const fixedContent = content.replace(
  `addEventListener("storage", function (e) {`,
  `addEventListener("storage", (e) => {`
);

writeFileSync(filepath, fixedContent);

package.json

{
  "scripts": {
    "postinstall": "node postinstall.js"
  }
}

[vrtmrz]

In my opinion, as a temporary solution, we could utilize the temporarily modified package located in our local drive.
Like this: https://github.com/vrtmrz/obsidian-livesync/blob/2c36ec497c5f57093794bbf14914614297670c9d/package.json#L38.

It might be better to be idempotent.