language/twig: add treesitter, LSP, diagnostics, and formatting support.

Due to better tools like twig-cs-fixer and curlylint not beeing packaged
in nix, this uses worse alterantives.

configuration.nix

@@ -101,6 +101,7 @@ isMaximal: {
       tailwind.enable = false;
       svelte.enable = false;
       tera.enable = false;
+      twig.enable = false;
 
       # Nim LSP is broken on Darwin and therefore
       # should be disabled by default. Users may still enable

docs/manual/release-notes/rl-0.9.md

@@ -222,6 +222,11 @@
 - Added Formatting support to `languages.php` via
   [PHP-CS-Fixer](https://github.com/PHP-CS-Fixer/PHP-CS-Fixer).
 
+- Added minimal `languages.twig`. Currently using [djlint](https://djlint.com/)
+  for most options, as better alternatives like
+  [twig-cs-fixer](https://github.com/VincentLanglet/Twig-CS-Fixer) aren't
+  packaged for nix.
+
 - Didn't Add
   [`syntax-gaslighting`](https://github.com/NotAShelf/syntax-gaslighting.nvim),
   you're crazy.

modules/plugins/languages/default.nix

@@ -23,6 +23,7 @@ in {
     ./kotlin.nix
     ./html.nix
     ./tera.nix
+    ./twig.nix
     ./haskell.nix
     ./java.nix
     ./jinja.nix

modules/plugins/languages/twig.nix

@@ -0,0 +1,120 @@
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}: let
+  inherit (builtins) attrNames;
+  inherit (lib.options) mkEnableOption mkOption;
+  inherit (lib.modules) mkIf mkMerge;
+  inherit (lib.meta) getExe;
+  inherit (lib.types) listOf enum;
+  inherit (lib.nvim.types) mkGrammarOption diagnostics;
+  inherit (lib.nvim.attrsets) mapListToAttrs;
+
+  cfg = config.vim.languages.twig;
+
+  defaultServers = ["twig-language-server"];
+  servers = {
+    twig-language-server = {
+      enable = true;
+      cmd = [(getExe pkgs.twig-language-server) "--stdio"];
+      filetypes = ["twig"];
+      root_markers = [".git"];
+    };
+  };
+
+  defaultFormat = ["djlint"];
+  formats = {
+    djlint = {
+      command = getExe pkgs.djlint;
+    };
+    # TODO: if twig-cs-fixer gets packaged for nix, add it and default to it.
+  };
+  defaultDiagnosticsProvider = ["djlint"];
+  diagnosticsProviders = {
+    djlint = {
+      config = {
+        cmd = getExe pkgs.djlint;
+      };
+    };
+    # TODO: if curlylint gets packaged for nix, add it.
+  };
+in {
+  options.vim.languages.twig = {
+    enable = mkEnableOption "Twig templating language support";
+
+    treesitter = {
+      enable = mkEnableOption "Twig treesitter" // {default = config.vim.languages.enableTreesitter;};
+      package = mkGrammarOption pkgs "twig";
+    };
+
+    lsp = {
+      enable = mkEnableOption "Twig LSP support" // {default = config.vim.lsp.enable;};
+      servers = mkOption {
+        type = listOf (enum (attrNames servers));
+        default = defaultServers;
+        description = "Twig LSP server to use";
+      };
+    };
+
+    format = {
+      enable = mkEnableOption "PHP formatting" // {default = config.vim.languages.enableFormat;};
+      type = mkOption {
+        description = "Twig formatter to use";
+        type = listOf (enum (attrNames formats));
+        default = defaultFormat;
+      };
+    };
+
+    extraDiagnostics = {
+      enable = mkEnableOption "extra Twig diagnostics" // {default = config.vim.languages.enableExtraDiagnostics;};
+      types = diagnostics {
+        langDesc = "Twig";
+        inherit diagnosticsProviders;
+        inherit defaultDiagnosticsProvider;
+      };
+    };
+  };
+
+  config = mkIf cfg.enable (mkMerge [
+    (mkIf cfg.treesitter.enable {
+      vim.treesitter.enable = true;
+      vim.treesitter.grammars = [cfg.treesitter.package];
+    })
+
+    (mkIf cfg.lsp.enable {
+      vim.lsp.servers =
+        mapListToAttrs (n: {
+          name = n;
+          value = servers.${n};
+        })
+        cfg.lsp.servers;
+    })
+
+    (mkIf cfg.format.enable {
+      vim.formatter.conform-nvim = {
+        enable = true;
+        setupOpts = {
+          formatters_by_ft.twig = cfg.format.type;
+          formatters =
+            mapListToAttrs (name: {
+              inherit name;
+              value = formats.${name};
+            })
+            cfg.format.type;
+        };
+      };
+    })
+
+    (mkIf cfg.extraDiagnostics.enable {
+      vim.diagnostics.nvim-lint = {
+        enable = true;
+        linters_by_ft.twig = cfg.extraDiagnostics.types;
+        linters =
+          mkMerge (map (name: {${name} = diagnosticsProviders.${name}.config;})
+            cfg.extraDiagnostics.types);
+      };
+    })
+  ]);
+}