rework document closing (connection doesn't go away)

Author: bollwyvl

atest/Keywords.robot

@@ -184,8 +184,8 @@ Setup Notebook
     Copy File    examples${/}${file}    ${OUTPUT DIR}${/}home${/}${file}
     Try to Close All Tabs
     Open ${file} in ${MENU NOTEBOOK}
-    Wait Until Fully Initialized
     Capture Page Screenshot    00-opened.png
+    Wait Until Fully Initialized
     Capture Page Screenshot    01-initialized.png
 
 Open Diagnostics Panel

packages/jupyterlab-lsp/src/adapters/codemirror/features/highlights.ts

@@ -73,6 +73,9 @@ export class Highlights extends CodeMirrorLSPFeature {
   };
 
   protected onCursorActivity = async () => {
+    if (!this.virtual_editor?.virtual_document?.document_info) {
+      return;
+    }
     let root_position: IRootPosition;
 
     try {

packages/jupyterlab-lsp/src/connection_manager.ts

@@ -256,9 +256,7 @@ export class DocumentConnectionManager {
   }
 
   public unregister_document(virtual_document: VirtualDocument) {
-    const connection = this.connections.get(virtual_document.id_path);
     this.connections.delete(virtual_document.id_path);
-    this.closed.emit({ connection, virtual_document });
   }
 }