the example used in the readme does not work

[frankgreco]

The hello world example does not work. In fact, no website I've tried works. It's usually always panics.

./lightpanda-aarch64-macos --host 127.0.0.1 --port 9222
info(websocket): starting blocking worker to listen on 127.0.0.1:9222
info(server): accepting new conn...
info(server): client connected
info(browser): GET https://wikipedia.com/ 200
info(browser): fetch [https://wikipedia.com/portal/wikipedia.org/assets/js/index-2...](https://wikipedia.com/portal/wikipedia.org/assets/js/index-24c3e2ca18.js): http.Status.ok
info(browser): eval script portal/wikipedia.org/assets/js/index-24c3e2ca18.js: ReferenceError: location is not defined
info(browser): fetch [https://wikipedia.com/portal/wikipedia.org/assets/js/gt-ie9-...](https://wikipedia.com/portal/wikipedia.org/assets/js/gt-ie9-ce3fe8e88d.js): http.Status.ok
error(events): event handler error: error.JSExecCallback
info(events): event handler error try catch: TypeError: Cannot read properties of undefined (reading 'length')
info(server): close cmd, closing conn...
info(server): accepting new conn...
thread 5274880 panic: attempt to use null value
zsh: abort ./lightpanda-aarch64-macos --host 127.0.0.1 --port 9222

[krichprollsch]

Hello @frankgreco,
Thanks for the issue.
Indeed I can reproduce, something goes wrong on handling the client's disconnection.

But I get the list of the links correctly. Did you get them?

[frankgreco]

If I try to dump the page contents, I get a different error.

'use strict'

import puppeteer from 'puppeteer-core';

const browser = await puppeteer.connect({
  browserWSEndpoint: "ws://127.0.0.1:9222",
});

const context = await browser.createBrowserContext();
const page = await context.newPage();

await page.goto('https://wikipedia.com/');

console.log(await page.content());

await page.close();
await context.close();

❯ node index.mjs
file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/common/CallbackRegistry.js:77
            this._reject(callback, new TargetCloseError('Target closed'));
                                   ^

TargetCloseError: Protocol error (Runtime.callFunctionOn): Target closed
    at CallbackRegistry.clear (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/common/CallbackRegistry.js:77:36)
    at CdpCDPSession._onClosed (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/CDPSession.js:106:25)
    at #onClose (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/Connection.js:171:21)
    at WebSocket.<anonymous> (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/node/NodeWebSocketTransport.js:43:30)
    at callListener (/Users/frank/projects/superblocks/browser/node_modules/ws/lib/event-target.js:290:14)
    at WebSocket.onClose (/Users/frank/projects/superblocks/browser/node_modules/ws/lib/event-target.js:220:9)
    at WebSocket.emit (node:events:520:28)
    at WebSocket.emitClose (/Users/frank/projects/superblocks/browser/node_modules/ws/lib/websocket.js:272:10)
    at Socket.socketOnClose (/Users/frank/projects/superblocks/browser/node_modules/ws/lib/websocket.js:1341:15)
    at Socket.emit (node:events:520:28) {
  cause: ProtocolError
      at <instance_members_initializer> (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/common/CallbackRegistry.js:97:14)
      at new Callback (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/common/CallbackRegistry.js:101:16)
      at CallbackRegistry.create (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/common/CallbackRegistry.js:20:26)
      at Connection._rawSend (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/Connection.js:89:26)
      at CdpCDPSession.send (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/CDPSession.js:66:33)
      at #evaluate (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/ExecutionContext.js:359:50)
      at ExecutionContext.evaluate (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/ExecutionContext.js:274:36)
      at IsolatedWorld.evaluate (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/IsolatedWorld.js:97:30)
      at CdpFrame.evaluate (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/api/Frame.js:345:43)
      at CdpFrame.<anonymous> (file:///Users/frank/projects/superblocks/browser/node_modules/puppeteer-core/lib/esm/puppeteer/util/decorators.js:101:27)
}

Node.js v22.6.0

❯ ./lightpanda-aarch64-macos --host 127.0.0.1 --port 9222
info(websocket): starting blocking worker to listen on 127.0.0.1:9222
info(server): accepting new conn...
info(server): client connected
info(browser): GET https://wikipedia.com/ 200
info(browser): fetch https://wikipedia.com/portal/wikipedia.org/assets/js/index-24c3e2ca18.js: http.Status.ok
info(browser): eval script portal/wikipedia.org/assets/js/index-24c3e2ca18.js: ReferenceError: location is not defined
info(browser): fetch https://wikipedia.com/portal/wikipedia.org/assets/js/gt-ie9-ce3fe8e88d.js: http.Status.ok
error(events): event handler error: error.JSExecCallback
info(events): event handler error try catch: TypeError: Cannot read properties of undefined (reading 'length')
info(server): close cmd, closing conn...
info(server): accepting new conn...
thread 5774907 panic: attempt to use null value
zsh: abort      ./lightpanda-aarch64-macos --host 127.0.0.1 --port 9222

[sanjomathew09]

'use strict';

import puppeteer from 'puppeteer-core';

async function main() {
try {
// Connect to the browser instance
const browser = await puppeteer.connect({
browserWSEndpoint: 'ws://127.0.0.1:9222', // WebSocket endpoint
});

// Create a new browser context (isolation)
const context = await browser.createIncognitoBrowserContext(); // Use incognito mode for a clean session

// Open a new page in the context
const page = await context.newPage();

// Navigate to the target URL
await page.goto('https://wikipedia.com/', {
  waitUntil: 'networkidle2', // Wait for network to be idle
});

// Extract the page content
const pageContent = await page.content();
console.log(pageContent);

// Clean up
await page.close(); // Close the page
await context.close(); // Close the browser context
await browser.disconnect(); // Disconnect from the browser

} catch (error) {
console.error('An error occurred:', error);
}
}

main();

[ManojBhamsagar-Draup]

Yes I'm also stuck with the same error:

const context = await browser.createBrowserContext();
^

TypeError: browser.createBrowserContext is not a function

At least, please provide a minimal example that works. Since this repo lacks documentation.

[frankgreco]

@sanjomathew09 Your code yields ⬇

info(browser): GET https://wikipedia.com/ 200
info(browser): fetch https://wikipedia.com/portal/wikipedia.org/assets/js/index-6bf78c58fd.js: http.Status.ok
info(browser): eval script portal/wikipedia.org/assets/js/index-6bf78c58fd.js: ReferenceError: location is not defined
info(browser): fetch https://wikipedia.com/portal/wikipedia.org/assets/js/gt-ie9-ce3fe8e88d.js: http.Status.ok
error(events): event handler error: error.JSExecCallback
info(events): event handler error try catch: TypeError: Cannot read properties of undefined (reading 'length')

Ideally just looking for a minimal hello world. I see that this project gets a lot of development so I'm assuming that there's a way to get it to work.

[krichprollsch]

@frankgreco I merged an improvement regarding the bug you had.
Can you re-test your script to dump html w/ puppeteer please?

[bruvduroiu]

Still seeing this error building for linux/amd64 via the Dockerfile, same script as the README file

≫ git rev-parse HEAD
43f42f9ca009dfff37ca703f3d72fee6e1dbfe88

info(server): client connected                                                                                                                                                                                                                          
info(browser): GET https://wikipedia.org/ 200                                                                                                                                                                                                           
info(browser): fetch https://wikipedia.org/portal/wikipedia.org/assets/js/index-6bf78c58fd.js: http.Status.ok                                                                                                                                           
info(browser): eval script portal/wikipedia.org/assets/js/index-6bf78c58fd.js: Error: NotImplemented                                                                                                                                                    
info(browser): fetch https://wikipedia.org/portal/wikipedia.org/assets/js/gt-ie9-ce3fe8e88d.js: http.Status.ok                                                                                                                                          
error(events): event handler error: error.JSExecCallback                                                                                                                                                                                                
info(events): event handler error try catch: TypeError: Cannot read properties of undefined (reading 'length')

EDIT: I should mention that I'm waiting for networkidle0 when fetching Wikipedia

[krichprollsch]

@bruvduroiu thanks for your feedback.
The errors are JS error due to Web APIs missing in Ligthpanda.
They shouldn't block the browser's execution, but the final result may not be exactly the expected one.