rfc: load grammars from babel plugins

[cdaringe]

Describe the issue

• for babel plugins that bring their own parser and/or modify syntax--e.g. old skool async/await, pipeline operator, algebraic effects, etc etc--there's no first class mechanism to get those syntaxes included into the editor without updating extension code.

what if babel plugins themselves hosted or pointed to vscode injection grammars for syntax support?

the workflow could look like:

• vscode opens
• vscode-language-babel loads
  • reads babel plugins
  • loads grammars from plugins
  • https://code.visualstudio.com/api/language-extensions/syntax-highlight-guide#injection-grammars

now, vscode auto-enhances syntax, rather than having to drop code here to support arbitrary features. that is, i want any babel user to install my custom babel plugin and have syntax supported automatically on-install.

what is not great about this proposal is that babel-plugins would then need to be vscode aware, which seems maybe not the best. it's not the worst either--it's pretty light to add a contributes: field in package.json and host an additional .json file in the npm tarball. however, this could be mitigated by plugins perhaps just referencing an optional dependency (or even just a string mapping in package.json, "vscode-injection-grammar": "some-npm-vscode-injection-grammar") that this pkg would attempt to load.

what do you think?

[michaelgmcd]

This is definitely an interesting idea and I could definitely see this being the future of JS syntax highlighting.

I see two major blockers. VSCode public APIs don't allow this project to update grammars at runtime (see https://github.com/microsoft/vscode/issues/61962). The second would be getting plugin authors to write and maintain their grammars. Most people use something like babel-preset-env these days which contains most of the "newer" syntax.

VSCode uses Textmate grammars, which is a standard across several editors. This means the plugins wouldn't necessarily need to VSCode aware.

We also need to be aware of advances in Node.js. Unlike front-end JS, Node.js (mainly V8) adds native support for newer JS features (like async/await). How would those work?

[cdaringe]

APIs don't allow this project to update grammars at runtime

bummer. thanks for sharing the link! i have subscribed and 👍 'd

getting plugin authors to write and maintain their grammars

agreed. i would hope that if a POC went well enough, the benefit/ROI of the improved UX would drive the community to at least be receptive to it. if babel authors felt uncomfortable about having VSCode-isms in their source because of the low correlation to the actual purpose of the plugin, perhaps some package.json interface could be used that this extension could parse and load--that way adding a grammar into their source would be less invasive, and interested parties could maintain the grammar in a stringly referenced repo from the babel plugin's package.json? i don't know--maybe i'm thinkin too far ahead :)

How would those work?

ya, interesting. one idea would be to synchronize VSCode's internal TM grammar internally here somehow. i bet if one ecosystem advances a feature to stable, vscode would move to support the syntax quickly, and 👏, no further effort? there also may already be a babel-plugin for said hypothetical feature in the users -env plugin stack iff they are using babel, so of course we could sniff there. i think it's less common for node users to babel tho. referring/building back on the package.json interface suggestion, perhaps we could allow users to punch in git urls to grammars to install at runtime for them? 🤔