From a2ce78fa90fe91ba855203cb7e30aa727c85ec31 Mon Sep 17 00:00:00 2001
From: Ching Pei Yang <badnam3o.0@gmail.com>
Date: Sat, 28 Jun 2025 15:30:24 +0200
Subject: [PATCH] language/go: migrate to vim.lsp.servers

---
 modules/plugins/languages/go.nix | 76 ++++++++++++++++++++------------
 1 file changed, 49 insertions(+), 27 deletions(-)

diff --git a/modules/plugins/languages/go.nix b/modules/plugins/languages/go.nix
index bab0ff4a..3ecc5d28 100644
--- a/modules/plugins/languages/go.nix
+++ b/modules/plugins/languages/go.nix
@@ -8,28 +8,53 @@
   inherit (lib.options) mkEnableOption mkOption literalMD;
   inherit (lib.modules) mkIf mkMerge;
   inherit (lib.meta) getExe;
-  inherit (lib.lists) isList;
-  inherit (lib.types) bool enum either listOf package str;
+  inherit (lib.generators) mkLuaInline;
+  inherit (lib.types) bool enum package listOf;
   inherit (lib.nvim.types) mkGrammarOption;
-  inherit (lib.nvim.lua) expToLua;
   inherit (lib.nvim.dag) entryAfter;
+  inherit (lib.nvim.attrsets) mapListToAttrs;
 
   cfg = config.vim.languages.go;
 
-  defaultServer = "gopls";
+  defaultServers = ["gopls"];
   servers = {
     gopls = {
-      package = pkgs.gopls;
-      lspConfig = ''
-        lspconfig.gopls.setup {
-          capabilities = capabilities;
-          on_attach = default_on_attach;
-          cmd = ${
-          if isList cfg.lsp.package
-          then expToLua cfg.lsp.package
-          else ''{"${cfg.lsp.package}/bin/gopls", "serve"}''
-        },
-        }
+      cmd = [(getExe pkgs.gopls)];
+      filetypes = ["go" "gomod" "gowork" "gotmpl"];
+      root_dir = mkLuaInline ''
+        function(bufnr, on_dir)
+          local fname = vim.api.nvim_buf_get_name(bufnr)
+
+          local function get_root(fname)
+            if _G.nvf_gopls_mod_cache and fname:sub(1, #_G.nvf_gopls_mod_cache) == _G.nvf_gopls_mod_cache then
+              local clients = vim.lsp.get_clients { name = 'gopls' }
+              if #clients > 0 then
+                return clients[#clients].config.root_dir
+              end
+            end
+            return vim.fs.root(fname, 'go.work') or vim.fs.root(fname, 'go.mod') or vim.fs.root(fname, '.git')
+          end
+
+          -- see: https://github.com/neovim/nvim-lspconfig/issues/804
+          if _G.nvf_gopls_mod_cache then
+            on_dir(get_root(fname))
+            return
+          end
+          local cmd = { 'go', 'env', 'GOMODCACHE' }
+          local ok, err = pcall(vim.system, cmd, { text = true }, function(output)
+            if output.code == 0 then
+              if output.stdout then
+                _G.nvf_gopls_mod_cache = vim.trim(output.stdout)
+              end
+              on_dir(get_root(fname))
+            else
+              vim.schedule(function()
+                vim.notify(('[gopls] cmd failed with code %d: %s\n%s'):format(output.code, cmd, output.stderr))
+              end)
+            end
+          end)
+          if not ok then vim.notify(('[gopls] cmd failed: %s\n%s'):format(cmd, err)) end
+        end
       '';
     };
   };
@@ -69,17 +94,10 @@ in {
     lsp = {
       enable = mkEnableOption "Go LSP support" // {default = config.vim.lsp.enable;};
 
-      server = mkOption {
+      servers = mkOption {
+        type = singleOrListOf (enum (attrNames servers));
+        default = defaultServers;
         description = "Go LSP server to use";
-        type = enum (attrNames servers);
-        default = defaultServer;
-      };
-
-      package = mkOption {
-        description = "Go LSP server package, or the command to run as a list of strings";
-        example = ''[lib.getExe pkgs.jdt-language-server " - data " " ~/.cache/jdtls/workspace "]'';
-        type = either package (listOf str);
-        default = servers.${cfg.lsp.server}.package;
       };
     };
 
@@ -134,8 +152,12 @@ in {
     })
 
     (mkIf cfg.lsp.enable {
-      vim.lsp.lspconfig.enable = true;
-      vim.lsp.lspconfig.sources.go-lsp = servers.${cfg.lsp.server}.lspConfig;
+      vim.lsp.servers =
+        mapListToAttrs (name: {
+          inherit name;
+          value = servers.${name};
+        })
+        cfg.lsp.servers;
     })
 
     (mkIf cfg.format.enable {