Merge pull request #13649 from mjlbach/move_from_nvim-lspconfig

LSP: Move workspace/configuration from nvim-lspconfig to core

runtime/doc/lsp.txt

@@ -755,6 +755,10 @@ start_client({config})                                *vim.lsp.start_client()*
                                          array.
                     {handlers}         Map of language server method names to
                                        |lsp-handler|
+                    {settings}         Map with language server specific
+                                       settings. These are returned to the language server if
+                                       requested via `workspace/configuration`. Keys are
+                                       case-sensitive.
                     {init_options}     Values to pass in the initialization
                                        request as `initializationOptions` .
                                        See `initialize` in the LSP spec.

runtime/lua/vim/lsp/handlers.lua

@@ -148,6 +148,31 @@ M['workspace/applyEdit'] = function(_, _, workspace_edit)
   }
 end
 
+--@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_configuration
+M['workspace/configuration'] = function(err, _, params, client_id)
+  local client = vim.lsp.get_client_by_id(client_id)
+  if not client then
+    err_message("LSP[id=", client_id, "] client has shut down after sending the message")
+  end
+  if err then error(vim.inspect(err)) end
+  if not params.items then
+    return {}
+  end
+
+  local result = {}
+  for _, item in ipairs(params.items) do
+    if item.section then
+      local value = util.lookup_section(client.config.settings, item.section) or vim.NIL
+      -- For empty sections with no explicit '' key, return settings as is
+      if value == vim.NIL and item.section == '' then
+        value = client.config.settings or vim.NIL
+      end
+      table.insert(result, value)
+    end
+  end
+  return result
+end
+
 M['textDocument/publishDiagnostics'] = function(...)
   return require('vim.lsp.diagnostic').on_publish_diagnostics(...)
 end

runtime/lua/vim/lsp/util.lua

@@ -1422,6 +1422,21 @@ function M.character_offset(buf, row, col)
   return str_utfindex(line, col)
 end
 
+--- Helper function to return nested values in language server settings
+---
+--@param settings a table of language server settings
+--@param section  a string indicating the field of the settings table
+--@returns (table or string) The value of settings accessed via section
+function M.lookup_section(settings, section)
+  for part in vim.gsplit(section, '.', true) do
+    settings = settings[part]
+    if not settings then
+      return
+    end
+  end
+  return settings
+end
+
 M._get_line_byte_from_position = get_line_byte_from_position
 M._warn_once = warn_once
 

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

@@ -109,6 +109,23 @@ function tests.basic_init()
   }
 end
 
+function tests.check_workspace_configuration()
+  skeleton {
+    on_init = function(_params)
+      return { capabilities = {} }
+    end;
+    body = function()
+      notify('start')
+      notify('workspace/configuration', { items = {
+              { section = "testSetting1" };
+              { section = "testSetting2" };
+          } })
+      expect_notification('workspace/configuration', { true; vim.NIL})
+      notify('shutdown')
+    end;
+  }
+end
+
 function tests.basic_check_capabilities()
   skeleton {
     on_init = function(params)

test/functional/plugin/lsp_spec.lua

@@ -262,6 +262,48 @@ describe('LSP', function()
       }
     end)
 
+    it('client should return settings via workspace/configuration handler', function()
+      local expected_callbacks = {
+        {NIL, "shutdown", {}, 1};
+        {NIL, "workspace/configuration", { items = {
+              { section = "testSetting1" };
+              { section = "testSetting2" };
+          }}, 1};
+        {NIL, "start", {}, 1};
+      }
+      local client
+      test_rpc_server {
+        test_name = "check_workspace_configuration";
+        on_init = function(_client)
+          client = _client
+        end;
+        on_exit = function(code, signal)
+          eq(0, code, "exit code", fake_lsp_logfile)
+          eq(0, signal, "exit signal", fake_lsp_logfile)
+        end;
+        on_callback = function(err, method, params, client_id)
+          eq(table.remove(expected_callbacks), {err, method, params, client_id}, "expected callback")
+          if method == 'start' then
+            exec_lua([=[
+              local client = vim.lsp.get_client_by_id(TEST_RPC_CLIENT_ID)
+              client.config.settings = {
+                testSetting1 = true;
+                testSetting2 = false;
+            }]=])
+          end
+          if method == 'workspace/configuration' then
+            local result = exec_lua([=[
+              local method, params = ...
+              return require'vim.lsp.handlers'['workspace/configuration'](err, method, params, TEST_RPC_CLIENT_ID)]=], method, params)
+            client.notify('workspace/configuration', result)
+          end
+          if method == 'shutdown' then
+            client.stop()
+          end
+        end;
+      }
+    end)
+
     it('should verify capabilities sent', function()
       local expected_callbacks = {
         {NIL, "shutdown", {}, 1};