fix(lsp): support workspace/configuation with no section

runtime/lua/vim/lsp/handlers.lua

@@ -206,6 +206,9 @@ M[ms.workspace_configuration] = function(_, result, ctx)
         value = vim.NIL
       end
       table.insert(response, value)
+    else
+      -- If no section is provided, return settings as is
+      table.insert(response, client.settings)
     end
   end
   return response

test/functional/fixtures/fake-lsp-server.lua

@@ -149,9 +149,16 @@ function tests.check_workspace_configuration()
           { section = 'testSetting2' },
           { section = 'test.Setting3' },
           { section = 'test.Setting4' },
+          {},
+          { section = '' },
         },
       })
-      expect_notification('workspace/configuration', { true, false, 'nested', vim.NIL })
+      local all = {
+        testSetting1 = true,
+        testSetting2 = false,
+        test = { Setting3 = 'nested' },
+      }
+      expect_notification('workspace/configuration', { true, false, 'nested', vim.NIL, all, all })
       notify('shutdown')
     end,
   }

test/functional/plugin/lsp_spec.lua

@@ -502,6 +502,8 @@ describe('LSP', function()
               { section = 'testSetting2' },
               { section = 'test.Setting3' },
               { section = 'test.Setting4' },
+              {},
+              { section = '' },
             },
           },
           { method = 'workspace/configuration', client_id = 1 },