WebDriver is a remote control interface that enables introspection and control of user agents. As such it can help developers to verify that their websites are working and performing well with all major browsers. The protocol is standardized by the W3C and consists of two separate specifications: WebDriver classic (HTTP) and the new WebDriver BiDi (Bi-Directional).

This newsletter gives an overview of the work we’ve done as part of the Firefox 120 release cycle.

Contributions

With Firefox being an open source project, we are grateful to get contributions from people outside of Mozilla.

WebDriver code is written in JavaScript, Python, and Rust so any web developer can contribute! Read how to setup the work environment and check the list of mentored issues for Marionette

WebDriver BiDi

Improved RemoteValue serialization

For commands like <a href="https://w3c.github.io/webdriver-bidi/#command-script-evaluate">script.evaluate</a> and <a href="https://w3c.github.io/webdriver-bidi/#command-script-callFunction">script.callFunction</a> the serialization of remote values has been improved to now also include a proper serialization of the JavaScript types for Proxy and Generator.

HTTP Authentication

In preparation of getting support for the network.authRequired event, the authChallenges field was added to the <a href="https://w3c.github.io/webdriver-bidi/#event-network-responseStarted">network.responseStarted</a> and <a href="https://w3c.github.io/webdriver-bidi/#event-network-responseCompleted">network.responseCompleted</a> events. This field holds a list of authentication challenges as present in the HTTP headers returned by the server for 401 responses.