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 147 release cycle.

Contributions

Firefox is an open source project, and we are always happy to receive external code contributions to our WebDriver implementation. We want to give special thanks to everyone who filed issues, bugs and submitted patches.

In Firefox 147, two WebDriver bugs were fixed by contributors:

• Sajid Anwar fixed an issue with browsingContext.navigate which could return a payload with an incorrect URL.
• Khalid AlHaddad added new WebDriver classic tests for the “Get All Cookies” command.

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, or the list of mentored JavaScript bugs for WebDriver BiDi. Join our chatroom if you need any help to get started!

General

• Fixed the new session response to include the required setWindowRect property.

WebDriver BiDi

• Implemented the input.fileDialogOpened event, which is emitted whenever a file picker is triggered by the content page, for instance after clicking on an input with type="file".
• Implemented the emulation.setScreenSettingsOverride command to allow clients to emulate the screen dimensions for a list of browsing contexts or user contexts.
• Fixed an issue where browsingContext.navigate with wait=none didn’t always contain the real target URL.
• Updated script.evaluate and script.callFunction to bypass Content Security Policy (CSP).
• Fixed missing script.realmCreated event for new browsing contexts created via window.open.
• Updated emulation.setLocaleOverride to override the Accept-Language header.
• Updated emulation.setLocaleOverride to throw an error when called with the locale argument equal to undefined.

Marionette

• Fixed JSON serialization of Chrome Windows.