Handle configuration changes in LSP for 'typescript.*' options.

internal/fourslash/fourslash.go

@@ -365,19 +365,24 @@ func sendRequest[Params, Resp any](t *testing.T, f *FourslashTest, info lsproto.
 	// !!! remove if `config` is handled in initialization and there are no other server-initiated requests
 	if resp.Kind == lsproto.MessageKindRequest {
 		req := resp.AsRequest()
-		switch req.Method {
-		case lsproto.MethodWorkspaceConfiguration:
-			req := lsproto.ResponseMessage{
-				ID:      req.ID,
-				JSONRPC: req.JSONRPC,
-				Result:  []any{f.userPreferences},
-			}
-			f.writeMsg(t, req.Message())
-			resp = f.readMsg(t)
-		default:
-			// other types of requests not yet used in fourslash; implement them if needed
-			t.Fatalf("Unexpected request received: %s", req.Method)
+
+		assert.Equal(t, req.Method, lsproto.MethodWorkspaceConfiguration, "Unexpected request received: %s", req.Method)
+		res := lsproto.ResponseMessage{
+			ID:      req.ID,
+			JSONRPC: req.JSONRPC,
+			Result:  []any{f.userPreferences},
 		}
+		f.writeMsg(t, res.Message())
+		req = f.readMsg(t).AsRequest()
+
+		assert.Equal(t, req.Method, lsproto.MethodClientRegisterCapability, "Unexpected request received: %s", req.Method)
+		res = lsproto.ResponseMessage{
+			ID:      req.ID,
+			JSONRPC: req.JSONRPC,
+			Result:  lsproto.Null{},
+		}
+		f.writeMsg(t, res.Message())
+		resp = f.readMsg(t)
 	}
 
 	if resp == nil {
@@ -413,9 +418,16 @@ func (f *FourslashTest) readMsg(t *testing.T) *lsproto.Message {
 }
 
 func (f *FourslashTest) Configure(t *testing.T, config *lsutil.UserPreferences) {
+	// !!!
+	// Callers to this function may need to consider
+	// sending a more specific configuration for 'javascript'
+	// or 'js/ts' as well. For now, we only send 'typescript',
+	// and most tests probably just want this.
 	f.userPreferences = config
 	sendNotification(t, f, lsproto.WorkspaceDidChangeConfigurationInfo, &lsproto.DidChangeConfigurationParams{
-		Settings: config,
+		Settings: map[string]any{
+			"typescript": config,
+		},
 	})
 }
 

internal/lsp/server.go

@@ -742,9 +742,29 @@ func (s *Server) handleInitialized(ctx context.Context, params *lsproto.Initiali
 			return err
 		}
 		s.session.InitializeWithConfig(userPreferences)
+
+		_, err = s.sendRequest(ctx, lsproto.MethodClientRegisterCapability, &lsproto.RegistrationParams{
+			Registrations: []*lsproto.Registration{
+				{
+					Id:     "typescript-config-watch-id",
+					Method: string(lsproto.MethodWorkspaceDidChangeConfiguration),
+					RegisterOptions: ptrTo(any(lsproto.DidChangeConfigurationRegistrationOptions{
+						Section: &lsproto.StringOrStrings{
+							// !!! Both the 'javascript' and 'js/ts' scopes need to be watched for settings as well.
+							Strings: &[]string{"typescript"},
+						},
+					})),
+				},
+			},
+		})
+		if err != nil {
+			return fmt.Errorf("failed to register configuration change watcher: %w", err)
+		}
 	}
 
-	// !!! temporary; remove when we have `handleDidChangeConfiguration`/implicit project config support
+	// !!! temporary.
+	// Remove when we have `handleDidChangeConfiguration`/implicit project config support
+	// derived from 'js/ts.implicitProjectConfig.*'.
 	if s.compilerOptionsForInferredProjects != nil {
 		s.session.DidChangeCompilerOptionsForInferredProjects(ctx, s.compilerOptionsForInferredProjects)
 	}
@@ -762,9 +782,14 @@ func (s *Server) handleExit(ctx context.Context, params any) error {
 }
 
 func (s *Server) handleDidChangeWorkspaceConfiguration(ctx context.Context, params *lsproto.DidChangeConfigurationParams) error {
-	// !!! only implemented because needed for fourslash
+	settings, ok := params.Settings.(map[string]any)
+	if !ok {
+		return nil
+	}
+	// !!! Both the 'javascript' and 'js/ts' scopes need to be checked for settings as well.
+	tsSettings := settings["typescript"]
 	userPreferences := s.session.UserPreferences()
-	if parsed := userPreferences.Parse(params.Settings); parsed != nil {
+	if parsed := userPreferences.Parse(tsSettings); parsed != nil {
 		userPreferences = parsed
 	}
 	s.session.Configure(userPreferences)