plugins/treesitter: add an internal `defaultGrammars` options

modules/plugins/treesitter/config.nix

@@ -1,5 +1,6 @@
 {
   config,
+  pkgs,
   lib,
   ...
 }: let
@@ -11,7 +12,7 @@
   cfg = config.vim.treesitter;
   usingNvimCmp = config.vim.autocomplete.enable && config.vim.autocomplete.type == "nvim-cmp";
 
-  self = import ./treesitter.nix {inherit lib;};
+  self = import ./treesitter.nix {inherit pkgs lib;};
   mappingDefinitions = self.options.vim.treesitter.mappings;
   mappings = addDescriptionsToMappings cfg.mappings mappingDefinitions;
 in {
@@ -32,7 +33,6 @@ in {
           (mkSetBinding mappings.incrementalSelection.decrementByNode ":lua require('nvim-treesitter.incremental_selection').node_decremental()<CR>")
         ];
       };
-
       # For some reason treesitter highlighting does not work on start if this is set before syntax on
       configRC.treesitter-fold = mkIf cfg.fold (entryBefore ["basic"] ''
         set foldmethod=expr
@@ -42,14 +42,18 @@ in {
 
       luaConfigRC.treesitter = entryAnywhere ''
         require'nvim-treesitter.configs'.setup {
+          -- Disable imperative treesitter options that would attempt to fetch
+          -- grammars into the read-only Nix store. To add additionall grammars here
+          -- you must use the `config.vim.treesitter.grammars` option.
+          auto_install = false,
+          sync_install = false,
+          ensure_installed = {},
+
           highlight = {
             enable = true,
             disable = {},
           },
 
-          auto_install = false,
-          ensure_installed = {},
-
           incremental_selection = {
             enable = true,
             keymaps = {

modules/plugins/treesitter/context.nix

@@ -1,89 +0,0 @@
-{
-  config,
-  lib,
-  ...
-}: let
-  inherit (lib.options) mkOption mkEnableOption;
-  inherit (lib.types) int bool str nullOr enum;
-  inherit (lib.modules) mkIf;
-  inherit (lib.trivial) boolToString;
-  inherit (lib.nvim.lua) nullString;
-  inherit (lib.nvim.dag) entryAnywhere;
-
-  inherit (config.vim) treesitter;
-  cfg = treesitter.context;
-in {
-  options.vim.treesitter.context = {
-    enable = mkEnableOption "context of current buffer contents [nvim-treesitter-context] ";
-
-    maxLines = mkOption {
-      description = "How many lines the window should span. Values <=0 mean no limit.";
-      type = int;
-      default = 0;
-    };
-
-    minWindowHeight = mkOption {
-      description = "Minimum editor window height to enable context. Values <= 0 mean no limit.";
-      type = int;
-      default = 0;
-    };
-
-    lineNumbers = mkOption {
-      description = "";
-      type = bool;
-      default = true;
-    };
-
-    multilineThreshold = mkOption {
-      description = "Maximum number of lines to collapse for a single context line.";
-      type = int;
-      default = 20;
-    };
-
-    trimScope = mkOption {
-      description = "Which context lines to discard if [](#opt-vim.treesitter.context.maxLines) is exceeded.";
-      type = enum ["inner" "outer"];
-      default = "outer";
-    };
-
-    mode = mkOption {
-      description = "Line used to calculate context.";
-      type = enum ["cursor" "topline"];
-      default = "cursor";
-    };
-
-    separator = mkOption {
-      description = ''
-        Separator between context and content. Should be a single character string, like '-'.
-
-        When separator is set, the context will only show up when there are at least 2 lines above cursorline.
-      '';
-      type = nullOr str;
-      default = null;
-    };
-
-    zindex = mkOption {
-      description = "The Z-index of the context window.";
-      type = int;
-      default = 20;
-    };
-  };
-
-  config = mkIf (treesitter.enable && cfg.enable) {
-    vim.startPlugins = ["nvim-treesitter-context"];
-
-    vim.luaConfigRC.treesitter-context = entryAnywhere ''
-      require'treesitter-context'.setup {
-        enable = true,
-        max_lines = ${toString cfg.maxLines},
-        min_window_height = ${toString cfg.minWindowHeight},
-        line_numbers = ${boolToString cfg.lineNumbers},
-        multiline_threshold = ${toString cfg.multilineThreshold},
-        trim_scope = '${cfg.trimScope}',
-        mode = '${cfg.mode}',
-        separator = ${nullString cfg.separator},
-        max_lines = ${toString cfg.zindex},
-      }
-    '';
-  };
-}

modules/plugins/treesitter/default.nix

@@ -1,7 +1,9 @@
 {
   imports = [
+    # treesitter extras
+    ./ts-context
+
     ./treesitter.nix
-    ./context.nix
     ./config.nix
   ];
 }

modules/plugins/treesitter/treesitter.nix

@@ -1,20 +1,16 @@
-{lib, ...}: let
+{
+  pkgs,
+  lib,
+  ...
+}: let
   inherit (lib.options) mkOption mkEnableOption;
   inherit (lib.nvim.binds) mkMappingOption;
   inherit (lib.types) listOf package;
+
+  inherit (pkgs.vimPlugins.nvim-treesitter) builtGrammars;
 in {
   options.vim.treesitter = {
     enable = mkEnableOption "treesitter, also enabled automatically through language options";
-    fold = mkEnableOption "fold with treesitter";
-    autotagHtml = mkEnableOption "autoclose and rename html tag";
-    grammars = mkOption {
-      type = listOf package;
-      default = [];
-      description = ''
-        List of treesitter grammars to install. For supported languages
-        use the `vim.language.<lang>.treesitter` option
-      '';
-    };
 
     mappings.incrementalSelection = {
       init = mkMappingOption "Init selection [treesitter]" "gnn";
@@ -22,5 +18,37 @@ in {
       incrementByScope = mkMappingOption "Increment selection by scope [treesitter]" "grc";
       decrementByNode = mkMappingOption "Decrement selection by node [treesitter]" "grm";
     };
+
+    fold = mkEnableOption "fold with treesitter";
+    autotagHtml = mkEnableOption "autoclose and rename html tag";
+    grammars = mkOption {
+      type = listOf package;
+      default = [];
+      description = ''
+        List of treesitter grammars to install.
+
+        For languages already supported by neovim-flake, you may
+        use the {option}`vim.language.<lang>.treesitter` options, which
+        will automatically add the required grammars to this.
+      '';
+    };
+
+    defaultGrammars = mkOption {
+      internal = true;
+      readOnly = true;
+      type = listOf package;
+      default = with builtGrammars; [c lua vim vimdoc query];
+      description = ''
+        A list of treesitter grammars that will be installed by default
+        if treesitter has been enabled.
+
+        ::: {.warning}
+        Regardless of which language module options you enable, Neovim
+        depends on those grammars to be enabled while treesitter is enabled.
+        This list cannot be modified, but its contents will only be appended
+        if the list of grammars does not contain the required grammars.
+        :::
+      '';
+    };
   };
 }