chrome-remote-debug-protocol

Chrome Remote Debug Protocol

Goals

• Auto-generate Client interface so third party tools can connect to Chrome, Node and other CRDP compliant servers
• Auto-generate Server interface so ChromeDevTools can connect to engines other than Chrome and Node

How

This package is purely a typings typescript d.ts interface that is automatically generated.

It has scripts to download the latest protocol.json files from the Chromium repo, verify structural integrity based on protocol.d.ts and generate a crdp.d.ts typescript interface.

Travis CI runs a nightly job to check that protocol.json from google doesn't have structural breaks. Thanks to this project, a few have already been detected and fixed.

Usage

crdp.d.ts is a JsonRpc2 compliant interface. It is meant to be used with noice-json-rpc package.

Rather than callbacks, noice-json-rpc returns Promises. This means it can be used async-await style.

noice-json-rpc also provides a .api() to return an ES6 proxy which provides a clean api.Domain.function() calls.

Building

Checkout this project. Install the dependencies (see .travis.yml) and run

npm run download-protocols
npm run generate-crdp

Example

import fs from 'fs'
import Crdp from 'chrome-remote-debug-protocol'
import {Client} from 'noice-json-rpc'

// run connects to `node --inspect --debug-brk` process, and profiles the execution of a script
async function run() {
   try {
       // We want the api to be a CrdpClient
       const api:Crdp.CrdpClient = new Client(new WebSocket("ws://localhost:8080"), {logConsole: true}).api()

       // Initialize debugging
       await Promise.all([
           api.Runtime.enable(),
           api.Debugger.enable(),
           api.Profiler.enable(),
           api.Runtime.run(),
       ])

       // Wait until the script finishes
       await new Promise((resolve) => api.Runtime.onExecutionContextDestroyed(resolve))

       // Get the cpuProfile back
       const cpuProfile = await api.Profiler.stop()

       // Save it to a file
       fs.writeFileSync("profile.cpuProfile", JSON.stringify(cpuProfile), 'utf-8')


   } catch (e) {
       console.error(e)
   }
}
run()