feat: add debugger for go

modules/languages/go.nix

@@ -21,6 +21,46 @@ with builtins; let
       '';
     };
   };
+  defaultDebugger = "delve";
+  debuggers = {
+    delve = {
+      package = pkgs.delve;
+      dapConfig = ''
+        dap.adapters.delve = {
+          type = "server",
+          port = "''${port}",
+          executable = {
+            command = "${getExe cfg.dap.package}",
+            args = { "dap", "-l", "127.0.0.1:''${port}" },
+          },
+        }
+
+        dap.configurations.go = {
+          {
+            type = "delve",
+            name = "Debug",
+            request = "launch",
+            program = "''${file}",
+          },
+          {
+            type = "delve",
+            name = "Debug test", -- configuration for debugging test files
+            request = "launch",
+            mode = "test",
+            program = "''${file}",
+          },
+          -- works with go.mod packages and sub packages
+          {
+            type = "delve",
+            name = "Debug test (go.mod)",
+            request = "launch",
+            mode = "test",
+            program = "./''${relativeFileDirname}",
+          },
+        }
+      '';
+    };
+  };
 in {
   options.vim.languages.go = {
     enable = mkEnableOption "Go language support";
@@ -46,6 +86,24 @@ in {
         default = servers.${cfg.lsp.server}.package;
       };
     };
+
+    dap = {
+      enable = mkOption {
+        description = "Enable Go Debug Adapter";
+        type = types.bool;
+        default = config.vim.languages.enableDAP;
+      };
+      debugger = mkOption {
+        description = "Go debugger to use";
+        type = with types; enum (attrNames debuggers);
+        default = defaultDebugger;
+      };
+      package = mkOption {
+        description = "Go debugger package.";
+        type = types.package;
+        default = debuggers.${cfg.dap.debugger}.package;
+      };
+    };
   };
 
   config = mkIf cfg.enable (mkMerge [
@@ -58,5 +116,10 @@ in {
       vim.lsp.lspconfig.enable = true;
       vim.lsp.lspconfig.sources.go-lsp = servers.${cfg.lsp.server}.lspConfig;
     })
+
+    (mkIf cfg.dap.enable {
+      vim.debugger.nvim-dap.enable = true;
+      vim.debugger.nvim-dap.sources.go-debugger = debuggers.${cfg.dap.debugger}.dapConfig;
+    })
   ]);
 }