terraform/hcl: improve options, fix terraform-cli error, add tofu-ls (free) as alternative option

- Add tofu(ls) as free terraform alternative for terraform and hcl
- Harmonize with other format/LSP implementation (also with conform)
- Add/fix terraform formatter
- Add `nomad fmt` as alternative hcl formatter

Note: for (nomad) hcl tofu/terraform ls are ineffective (don't support
e.g. jobspec schema) -> TODO: nomad-lsp (package and add, even though it
seems abandoned it's probably better for nomad/hcl)

modules/plugins/languages/hcl.nix

@@ -4,24 +4,31 @@
   lib,
   ...
 }: let
-  inherit (builtins) attrNames;
+  inherit (builtins) attrNames elem;
   inherit (lib.options) mkEnableOption mkOption;
   inherit (lib.meta) getExe;
-  inherit (lib.modules) mkIf mkMerge;
+  inherit (lib.modules) mkIf mkMerge mkDefault;
   inherit (lib.types) bool enum listOf;
   inherit (lib.nvim.types) mkGrammarOption deprecatedSingleOrListOf;
   inherit (lib.nvim.attrsets) mapListToAttrs;
 
   cfg = config.vim.languages.hcl;
 
-  defaultServers = ["terraform-ls"];
+  defaultServers = ["tofuls"];
   servers = {
-    terraform-ls = {
+    terraformls = {
       enable = true;
-      cmd = [(getExe pkgs.terraform-ls) "serve"];
-      filetypes = ["terraform" "terraform-vars"];
+      cmd = mkDefault [(getExe pkgs.terraform-ls) "serve"]; # NOTE: mkDefault to avoid clashes with terraform defs
+      filetypes = ["hcl"];
+      root_markers = [".git"];
+    };
+    tofuls = {
+      enable = true;
+      cmd = mkDefault [(getExe pkgs.tofu-ls) "serve"]; # NOTE: mkDefault to avoid clashes with terraform defs
+      filetypes = ["hcl"];
       root_markers = [".terraform" ".git"];
     };
+    # TODO: package nomad-lsp and offer as an option here too
   };
 
   defaultFormat = ["hclfmt"];
@@ -29,18 +36,25 @@
     hclfmt = {
       command = getExe pkgs.hclfmt;
     };
+    nomad-fmt = {
+      command = getExe pkgs.nomad;
+      args = ["fmt" "$FILENAME"];
+      stdin = false;
+    };
   };
 in {
   options.vim.languages.hcl = {
     enable = mkEnableOption "HCL support";
 
     treesitter = {
-      enable = mkEnableOption "HCL treesitter" // {default = config.vim.languages.enableTreesitter;};
+      enable =
+        mkEnableOption "HCL treesitter" // {default = config.vim.languages.enableTreesitter;};
       package = mkGrammarOption pkgs "hcl";
     };
 
     lsp = {
-      enable = mkEnableOption "HCL LSP support" // {default = config.vim.lsp.enable;};
+      enable =
+        mkEnableOption "HCL LSP support" // {default = config.vim.lsp.enable;};
       servers = mkOption {
         type = listOf (enum (attrNames servers));
         default = defaultServers;
@@ -81,18 +95,24 @@ in {
           .set('hcl', '#%s')
       '';
     }
+
     (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.${n};
-        })
-        cfg.lsp.servers;
+      vim = {
+        lsp.servers =
+          mapListToAttrs (n: {
+            name = n;
+            value = servers.${n};
+          })
+          cfg.lsp.servers;
+        extraPackages =
+          (lib.optionals (elem "terraformls" cfg.lsp.servers) [pkgs.terraform])
+          ++ (lib.optionals (elem "tofuls" cfg.lsp.servers) [pkgs.opentofu]);
+      };
     })
 
     (mkIf cfg.format.enable {

modules/plugins/languages/terraform.nix

@@ -4,44 +4,80 @@
   lib,
   ...
 }: let
-  inherit (builtins) attrNames;
+  inherit (builtins) attrNames concatStringsSep elem;
   inherit (lib.options) mkEnableOption mkOption;
   inherit (lib.modules) mkIf mkMerge;
   inherit (lib.meta) getExe;
-  inherit (lib.types) enum listOf;
-  inherit (lib.nvim.types) mkGrammarOption;
+  inherit (lib.types) bool enum listOf;
+  inherit (lib.nvim.types) mkGrammarOption deprecatedSingleOrListOf;
   inherit (lib.nvim.attrsets) mapListToAttrs;
 
   cfg = config.vim.languages.terraform;
 
-  defaultServers = ["terraformls"];
+  defaultServers = ["tofuls"];
   servers = {
     terraformls = {
       enable = true;
       cmd = [(getExe pkgs.terraform-ls) "serve"];
-      filetypes = ["terraform" "terraform-vars"];
+      filetypes = ["terraform" "terraform-vars" "tf"];
       root_markers = [".terraform" ".git"];
     };
+    tofuls = {
+      enable = true;
+      cmd = [(getExe pkgs.tofu-ls) "serve"];
+      filetypes = ["terraform" "terraform-vars" "tf"];
+      root_markers = [".terraform" ".git"];
+    };
+  };
+
+  defaultFormat = ["tofu-fmt"];
+  formats = {
+    tofu-fmt = {
+      command = "${getExe pkgs.opentofu}";
+      args = ["fmt" "$FILENAME"];
+      stdin = false;
+    };
+    terraform-fmt = {
+      command = "${getExe pkgs.terraform}";
+      args = ["fmt" "$FILENAME"];
+      stdin = false;
+    };
   };
 in {
   options.vim.languages.terraform = {
-    enable = mkEnableOption "Terraform/HCL support";
+    enable = mkEnableOption "Terraform support";
 
     treesitter = {
-      enable = mkEnableOption "Terraform treesitter" // {default = config.vim.languages.enableTreesitter;};
+      enable =
+        mkEnableOption "Terraform treesitter" // {default = config.vim.languages.enableTreesitter;};
       package = mkGrammarOption pkgs "terraform";
     };
 
     lsp = {
-      enable = mkEnableOption "Terraform LSP support (terraform-ls)" // {default = config.vim.lsp.enable;};
+      enable =
+        mkEnableOption "Terraform LSP support (terraform-ls)" // {default = config.vim.lsp.enable;};
 
       servers = mkOption {
         type = listOf (enum (attrNames servers));
         default = defaultServers;
-        description = "Terraform LSP server to use";
+        description = "Terraform LSP server to use (one or more of [${concatStringsSep " " (attrNames servers)}])";
+      };
+    };
+
+    format = {
+      enable = mkOption {
+        type = bool;
+        default = config.vim.languages.enableFormat;
+        description = "Enable Terraform formatting";
+      };
+      type = mkOption {
+        type = deprecatedSingleOrListOf "vim.language.terraform.format.type" (enum (attrNames formats));
+        default = defaultFormat;
+        description = "Terraform formatter to use";
       };
     };
   };
+
   config = mkIf cfg.enable (mkMerge [
     (mkIf cfg.treesitter.enable {
       vim.treesitter.enable = true;
@@ -49,12 +85,32 @@ in {
     })
 
     (mkIf cfg.lsp.enable {
-      vim.lsp.servers =
-        mapListToAttrs (n: {
-          name = n;
-          value = servers.${n};
-        })
-        cfg.lsp.servers;
+      vim = {
+        lsp.servers =
+          mapListToAttrs (n: {
+            name = n;
+            value = servers.${n};
+          })
+          cfg.lsp.servers;
+        extraPackages =
+          (lib.optionals (elem "terraformls" cfg.lsp.servers) [pkgs.terraform])
+          ++ (lib.optionals (elem "tofuls" cfg.lsp.servers) [pkgs.opentofu]);
+      };
+    })
+
+    (mkIf cfg.format.enable {
+      vim.formatter.conform-nvim = {
+        enable = true;
+        setupOpts = {
+          formatters_by_ft.terraform = cfg.format.type;
+          formatters =
+            mapListToAttrs (name: {
+              inherit name;
+              value = formats.${name};
+            })
+            cfg.format.type;
+        };
+      };
     })
   ]);
 }