chrome-remote-interface

Remote Debugging Protocol interface that helps to instrument Chrome by providing a simple abstraction of the two main objects exposed by the protocol in a Node.js fashion: commands and notifications.

Installation

npm install chrome-remote-interface

Chrome setup

Chrome needs to be started with the --remote-debugging-port=<port> option to enable the Remote Debugging Protocol, for example:

google-chrome --remote-debugging-port=9222

Sample usage

The following snippet loads https://github.com and dumps every request made.

var Chrome = require('chrome-remote-interface');
Chrome(function (chrome) {
    with (chrome) {
        on('Network.requestWillBeSent', function (message) {
            console.log(message.request.url);
        });
        on('Page.loadEventFired', close);
        Network.enable();
        Page.enable();
        Page.navigate({'url': 'https://github.com'});
    }
}).on('error', function () {
    console.error('Cannot connect to Chrome');
});

API

module([options], [callback])

Connects to a remote instance of Chrome using the Remote Debugging Protocol.

options is an object with the following optional properties:

host: Remote Debugging Protocol host. Defaults to localhost;
port: Remote Debugging Protocol port. Defaults to 9222;
chooseTab: callback used to determine which remote tab attach to. Takes the JSON array returned by http://host:port/json containing the tab list and must return the numeric index of a tab. Defaults to a function that returns the active one (function (tabs) { return 0; }).

callback is a listener automatically added to the connect event of the returned EventEmitter.

Returns an EventEmitter that supports the following events:

Event: 'connect'

function (chrome) {}

Emitted when the connection to Chrome is established.

chrome is an instance of the Chrome class.

Event: 'error'

function (error) {}

Emitted if http://host:port/json can't be reached or if it's not possible to connect to Chrome's remote debugging WebSocket.

error is an instance of Error.

Class: Chrome

Event: 'event'

function (message) {}

Emitted when Chrome sends a notification through the WebSocket.

message is the object received, it has the following properties:

method: a string describing the message.
params: an object containing the payload.

Refer to the Remote Debugging Protocol specifications for more information.

Event: method

function (params) {}

Emitted when Chrome sends a notification classified as method through the WebSocket.

params is an object containing the payload.

This is just a utility event that allows to easily filter out specific notifications (see the documentation of event), for example:

chrome.on('Network.requestWillBeSent', console.log);

chrome.send(method, [params], [callback])

Issue a command to Chrome.

method is a string describing the message.

params is an object containing the payload.

callback is executed when Chrome sends a response to this command, it gets the following arguments:

error: a boolean value indicating the success status;
response: an object containing either the response sent from Chrome or the indication of the error.

Note that the field id mentioned in the Remote Debugging Protocol specifications is managed internally and it's not exposed to the user.

chrome.Domain.method([params], [callback])

Just a shorthand for:

chrome.send('Domain.method', params, callback)

For example:

chrome.Page.navigate({'url': 'https://github.com'})

chrome.close()

Close the connection to Chrome.

Resources

Chrome Developer Tools: Remote Debugging Protocol v1.0

sidorares / chrome-remote-interface