lsp/presets/gopls: init

modules/plugins/lsp/presets/default.nix

@@ -7,6 +7,7 @@
     ./bash-language-server.nix
     ./deno.nix
     ./emmet-ls.nix
+    ./gopls.nix
     ./harper.nix
     ./helm-ls.nix
     ./intelephense.nix

modules/plugins/lsp/presets/gopls.nix

@@ -0,0 +1,59 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: let
+  inherit (lib.meta) getExe;
+  inherit (lib.modules) mkIf;
+  inherit (lib.options) mkEnableOption;
+  inherit (lib.generators) mkLuaInline;
+
+  cfg = config.vim.lsp.presets.gopls;
+in {
+  options.vim.lsp.presets.gopls = {
+    enable = mkEnableOption "the official Go Language Server";
+  };
+
+  config = mkIf cfg.enable {
+    vim.lsp.servers.gopls = {
+      enable = true;
+      cmd = [(getExe pkgs.gopls)];
+      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
+      '';
+    };
+  };
+}