web-ext

Web-ext

This is a command line tool to help build, run, and test web extensions.

Ultimately, it aims to support web extensions in a standard, portable, cross-platform way. Initially, it will provide a streamlined experience for developing Firefox web extensions.

Should I Use It?

This tool may require using a nightly build of Firefox and is initially intended to develop web extensions, a platform which is not yet stable in Firefox. If you are looking to develop an add-on that runs in older versions of Firefox, consider jpm.

Get Involved

Hi! This tool is under active development. To get involved you can watch the repo, file issues, create pull requests, or ask a question on dev-addons.

Some Questions and Answers

Why do we need a command line tool?

This is a great question and one that we will ask ourselves for each new web-ext feature. Most web extension functionality is baked into the browsers themselves but a complimentary command line tool will still be helpful. Here is a partial list of examples:

• File watching.
  • When you edit a file, you may need to trigger certain commands (tests, installation, etc).
• Integrating with services.
  • Mozilla offers some useful web services such as validating and signing extensions.

Why not patch jpm for web extension support?

First, note that jpm is still actively maintained by Mozilla right now. We decided not to patch jpm for web extension support. Here's why.

Mozilla built cfx then deprecated it for jpm and now we're proposing a new tool. I know this is frustrating for developers but web extensions mark a major turning point. It would be an arduous task to wedge its feature set and simplified development process into jpm.

Detailed reasons:

• By creating a new tool that focuses on the [emerging] web extension standard, we have a better chance of interoperating with other platforms, such as Google Chrome or Opera. It would be hard to do that while preserving compatibility in jpm.
• Creating SDK-based add-ons was overly complicated. With web extensions you no longer need to convert your source into legacy artifacts and you won't need boostrapping scripts.
• There are superior features in Firefox now for developing extensions such as loading from source code instead of a packaged XPI. It will be easier to reimagine a new tool around these work flows rather than adjust jpm's existing work flows.
• jpm's functional tests are slow, brittle and hard to run. There are flaky time-outs and we've run out of low hanging fruit fixes at this point.
• Most of jpm's code was not designed to be unit testable which makes it hard to maintain and refactor.
• jpm's code was written in ES5 which is cumbersome after coming from the ES6 Firefox code base or from most other languages with modern conveniences (Python, Ruby, etc).