PyCharm / IntelliJ inspection type error for Extension examples

JupyterLab
1

I am using PyCharm IDE (2022.1.4) to create a custom extension and have been following this typescript example Developing JupyterLab Extensions
PyCharm shows a type error for the plugin function. It seems PyCharm shows the error when IMainMenu is added as a required or optional type. I believe the error is likely false as the example builds fine using jlpm run build
Has anyone else encountered this weird behavior and know how to resolve it?

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image1925×399 57 KB

2

Can you show your foll code which leads to this issue? This looks like it could be potentially caused by type-only import, or maybe PyCharm has a problem with declaration merging detection?

3 
import {
  JupyterFrontEnd, 
  JupyterFrontEndPlugin 
} from '@jupyterlab/application'; 
 
import { ICommandPalette } from '@jupyterlab/apputils';
import { INotebookTracker, NotebookActions } from '@jupyterlab/notebook';
import { IMainMenu } from '@jupyterlab/mainmenu';
import { Menu } from '@lumino/widgets';
 
/** 
 * Initialization data for the snippetsexample extension. 
 */
const plugin: JupyterFrontEndPlugin<void> = {
  id: 'snippetsexample:plugin', 
  autoStart: true, 
  requires: [ICommandPalette, INotebookTracker, IMainMenu], 
  activate: (app: JupyterFrontEnd, palette: ICommandPalette, tracker: INotebookTracker, mainMenu: IMainMenu) => {
    console.log('JupyterLab extension myexample is activated!');
 
    const { commands } = app;
    
    commands.addCommand('openLink', {
      label: 'Documentation', 
      caption: 'Documentation', 
      execute: () => {
        const win = window.open('https://jupyterlab.readthedocs.io/en/stable/', '_blank');
        win?.focus();
      }
    });
 
    commands.addCommand('printHelloWorld', {
      label: 'Hello World!', 
      caption: 'Hello World!', 
      execute: () => {
        const current = tracker.currentWidget;
        const notebook = current!.content;
        NotebookActions.insertBelow(notebook);
        const activeCell = notebook.activeCell;
        activeCell!.model.value.text = 'print("Hello World!")';
      }
    }); 
    
    commands.addCommand('printTest', {
      label: 'Test', 
      caption: 'Test', 
      execute: () => {
        const current = tracker.currentWidget;
        const notebook = current!.content;
        NotebookActions.insertBelow(notebook);
        const activeCell = notebook.activeCell;
        activeCell!.model.value.text = 'print("Test")';
      }
    });
 
    const snippetMenu = new Menu({ commands });
    snippetMenu.title.label = 'Snippets';
    snippetMenu.addItem({command: 'openLink' }); 
    
    const printSubMenu = new Menu({ commands });
    printSubMenu.title.label = 'Print';
    printSubMenu.addItem({ command: 'printHelloWorld' });
    printSubMenu.addItem({ command: 'printTest' });
 
    snippetMenu.addItem({ type: 'submenu', submenu: printSubMenu});
    mainMenu.addMenu(snippetMenu, {rank: 300});
  }
}; 
 
export default plugin;