Using pouchdb-browser (+ pouchdb-adapter-memory) expects nodeJS APIs

[replete]

Info

• Environment: Browser, ESM, vite
• Platform: Chrome/FF
• Adapter: (pouchdb-adapter-memory + default idb?)
• Server: (vite)

Issue

I have a project and want to use PouchDB initially only in the browser with in-memory DB persisting to IndexedDB. As my starting point for figuring pouchDB out, introduce servers later.

Using pouchdb-browser, I've been getting the same issue from #8641 that was marked resolved in #8849: Uncaught TypeError: import_events.default is not a constructor

I saw that index.es.js has import EE from 'events'; but using events triggers Uncaught TypeError: setImmediate is not a function, so I used eventemitter3 and aliased it to events in vite.

Then I saw this familiar error: Uncaught ReferenceError: process is not defined, which I was not expecting given that I want to use this in the browser and that pouchdb-browser and pouchdb-adapter-memory both say they work in the browser. This seems to be raised by leveldb-adapter related code.

Patching process and global in vite leads us to:
Uncaught TypeError: superCtor.prototype is not an object or null from inherits/inherits.browser.js which appears to be this 2022 issue from the inherits package dependency. To fix this, I removed the Object.create version of the polyfill and used the other option.

Now, I'm left with Uncaught TypeError: this.setMaxListeners is not a function in LevelUP levelup.js:37

I couldn't find anything in the documentation about this, so is this a bug or is the 'works in the browser' part of pouchdb-adapter-memory conditional on polyfilling a load of Node APIs in the browser in your bundler?

Thank you for developing this project and I'd appreciate your comments.

[jelovac]

Have you been able to resolve the issue? I think I'm experiencing the same problem. My entire Vite-TypeScript-React client-side application crashes when I attempt to use PouchDB. I've tried it in both Firefox and Chrome, but I encounter the same error:

Uncaught TypeError: import_events.default is not a constructor at index.es.js:346

And when I open that line:

class Changes extends EE {
  constructor() {
    super();

    this._listeners = {};

    if (hasLocalStorage()) {
      addEventListener("storage", (e) => {
        this.emit(e.key);
      });
    }
  }

This is how I initilize it it:

import PouchDB from 'pouchdb-browser';

export class MyDataService {
    private readonly db: PouchDB.Database<MyDataDocument>;

    constructor(dbName: string = 'my_data') {
        this.db = new PouchDB<MyDataDocument>(dbName);
    }
    
    // CRUD actions
    // ...
}

const myDataService = new MyDataService('my_data');

Update

Installing "events" package from npm registry seems to fix the issue.

[replete]

@jelovac I went with something else in my project as this felt like it could be a problematic dependency situation and unsuitable for my needs

[alxndrsn]

Possibly related to:

• pouchdb-utils depends on events npm package for the browser build, but does not declare it as a dependency. #8985
• Dynamic require of "events" is not supported #8968

[NiloCK]

FYI: I have had some success against this issue with:

yarn add -D events-browserify

along with the specific config items:

// vite.config.js

import { defineConfig } from 'vite';

// https://vitejs.dev/config/
export default defineConfig({
  resolve: {
    alias: {
      events: 'events-browserify',
    },
  },
  optimizeDeps: {
    include: ['events-browserify'],
  },
});

[rougsig]

There is possible to create a pull request and solve that issue without hacks with bundles on client side?