Smarter Chromium GN in Vim with gn-language-server

GN Language Server for Chromium development was announced on chromium-dev. It’s very easy to install in VSCode, NeoVim or Emacs. But how can we configure it with classic Vim + YCM?

Setup

First, install the language server with Cargo.

cargo install --locked gn-language-server

Then, add this to your vimrc.

let g:ycm_language_server = [
      \ {
      \   'name': 'gn',
      \   'cmdline': [ 'gn-language-server' ],
      \   'filetypes': [ 'gn' ],
      \ }
  \ ]

That easy, right?

What’s Working

Hover Documentation

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Current Limitations

The following features are not working yet. They may need more configuration or further work:

Code Folding

Classic Vim and YCM don’t support LSP-based folding, and I’m not a big fan of that feature anyway. But you can configure another plugin that supports LSP-based folding, or simply rely on indent-based folding.

Go To Definition

When I try to go to the definition of template, I get an error KeyError: 'uri'. I’m not sure whether this is caused by my local configuration, but it needs further investigation.