tree-sitter-cue

Cue grammar for tree-sitter.

Development

This project uses Nix flakes to provide a reproducible development environment with tree-sitter, node, bc, and python3. You need Nix with flakes and nix-command experimental features enabled (see Nix flakes - Enable flakes).

nix develop
npm install

After modifying grammar.js, regenerate the parser and run tests:

tree-sitter generate
tree-sitter test

Testing

# Run all tests (corpus tests, the CUE syntax corpus, real CUE files)
npm test

# Run only the tree-sitter corpus and highlight tests
tree-sitter test

# Parse the copy of the CUE syntax corpus in test/syntax
script/parse-syntax-corpus

# Remove the files that now parse from test/syntax/KNOWN_GAPS
script/parse-syntax-corpus --update

# Parse example CUE files from cue-lang/cue
script/parse-examples

# Lint grammar.js
npm run lint

test/syntax is a copy of the syntax corpus that cue-lang/cue keeps at cue/parser/testdata/syntax: one file per syntax shape, in pass/ (valid), preview/ (valid with a preview experiment) or fail/ (rejected). script/parse-syntax-corpus fails if a valid file has an ERROR or MISSING node, unless test/syntax/KNOWN_GAPS lists it, and if a listed file parses cleanly; a missing KNOWN_GAPS lists no file. With --update, the script removes the listed files that parse cleanly instead, and deletes KNOWN_GAPS once it lists none. test/syntax/SOURCE records where the copy came from; script/sync-syntax-corpus <cue-checkout> refreshes it from a cue-lang/cue checkout at a tag.

Editor Setup

Neovim

Using lazy.nvim

return {
  "nvim-treesitter/nvim-treesitter",
  build = ":TSUpdate",
  event = { "BufReadPost", "BufNewFile" },
  --- @type TSConfig
  opts = {
    ensure_installed = {
      "cue",
    },
  },
  ---@param opts TSConfig
    config = function(_, opts)
      require("nvim-treesitter.configs").setup(opts)
    end,
}