Feature Request: Allow extensions to recommend or require other extensions

[davidcornu]

Check for existing issues

• Completed

Misc notes

Use case

I'm working on an extension to add Haml syntax highlighting (https://github.com/davidcornu/zed-haml). Given that Haml templates can embed Ruby, I've configured languages/haml/injections.scm to treat the appropriate regions as Ruby. However, this only works if you have the Ruby extension installed.

I would like to have a way to express this somewhere in the extension (perhaps in extension.toml) so that Zed could prompt users if they don't have the Ruby extension installed.

Prior art

VSCode extensions can set extensionPack or extensionDependencies as part of their manifest (https://code.visualstudio.com/api/references/extension-manifest) for this exact purpose.