Restore after change to prevent errors, handle the failures

Author: krassowski

packages/jupyterlab-lsp/src/editor_integration/codemirror.ts

@@ -23,6 +23,7 @@ import {
 } from '../virtual/codemirror_editor';
 import { StatusMessage, WidgetAdapter } from '../adapters/adapter';
 import { IDocumentWidget } from '@jupyterlab/docregistry';
+import { IEditorChange } from '../virtual/editor';
 
 function toDocumentChanges(changes: {
   [uri: string]: lsProtocol.TextEdit[];
@@ -407,6 +408,10 @@ export abstract class CodeMirrorIntegration
     return 1;
   }
 
+  afterChange(change: IEditorChange, root_position: IRootPosition) {
+    // nothing here
+  }
+
   protected apply_single_edit(edit: lsProtocol.TextEdit): number {
     let document = this.virtual_document;
     let applied_changes = 0;

packages/jupyterlab-lsp/src/editor_integration/editor_adapter.ts

@@ -75,7 +75,11 @@ export class EditorAdapter<T extends IVirtualEditor<IEditor>> {
       }
 
       for (let feature of this.features.values()) {
-        feature.afterChange(change, root_position);
+        try {
+          feature.afterChange(change, root_position);
+        } catch (err) {
+          console.warn('afterChange of feature', feature, 'failed with', err);
+        }
       }
       return true;
     } catch (e) {