nvim/lua/plugins/treesitter.lua

local options = {
    highlight = {
        enable = true,
        disable = { "fortran" },
        additional_vim_regex_highlighting = false,
    },
    incremental_selection = {
        enable = true,
        keymaps = {
            init_selection = "gnn",
            node_incremental = "gnr",
            scope_incremental = "gnc",
            node_decremental = "gnm",
        },
    },
    indent = {
        enable = true,
    },
    refactor = {
        smart_rename = {
            enable = true,
            keymaps = {
                smart_rename = "grr",
            },
        },
        navigation = {
            enable = true,
            keymaps = {
                goto_definition_lsp_fallback = "gnd",
            },
        },
    },
}

if vim.fn.executable "nix" == 1 then
    options.auto_install = true
    options.ensure_installed = "all"
end

return {
    "nvim-treesitter/nvim-treesitter",
    version = false,
    build = ":TSUpdate",
    cmd = { "TSUpdate", "TSInstall" },
    event = { "BufReadPre", "BufNewFile" },
    dependencies = "nvim-treesitter/nvim-treesitter-refactor",
    config = function(_, opts)
        if type(opts.ensure_installed) == "table" then
            -- @type table<string, boolean>
            local added = {}
            opts.ensure_installed = vim.tbl_filter(function(lang)
                if added[lang] then return false end
                added[lang] = true
                return true
            end, opts.ensure_installed)
        end
        require("nvim-treesitter.configs").setup(opts)
    end,
    opts = options,
}