require-disposable-ownership

Require newly created disposable objects to be owned, returned, assigned to a field, or disposed.

Why

Lumino IDisposable objects represent lifecycle cleanup. Creating a disposable and then dropping it usually leaks resources or callbacks that should have been released later.

Rule details

The rule checks new expressions that create known disposable classes such as DisposableDelegate, ObservableDisposableDelegate, DisposableSet, and ObservableDisposableSet. When TypeScript type information is available, it also detects objects typed as IDisposable or IObservableDisposable. It ignores disposable objects created directly inside a typed Jupyter plugin activate function, where services commonly live for the application lifetime.

It accepts common ownership patterns:

• Adding the object to a typed DisposableSet or a conventionally named disposable collection such as this._disposables.add(...)
• Passing the object as a direct array item to DisposableSet.from(...) or ObservableDisposableSet.from(...)
• Returning it
• Assigning it to an object field or class field initializer
• Storing it in a class-field collection with this._items.set(...)
• Calling .dispose() immediately
• Storing it in a variable that is later added, returned, assigned to a field, or disposed
• Passing it to a configured ownership helper function or default ownership sink such as add, addCell, addItem, addMenu, addWidget, insertWidget, or registerStatusItem
• Passing it through a known owned constructor options object, such as new MainAreaWidget({ content }) or new Dialog({ body })
• Passing it as a showDialog({ body: ... }) body or launching a typed Dialog with .launch()

Incorrect

new DisposableDelegate(() => {
  cleanup();
});

const disposable = new DisposableDelegate(() => {
  cleanup();
});
console.log(disposable);

Correct

this._disposables.add(
  new DisposableDelegate(() => {
    cleanup();
  })
);

return new DisposableDelegate(() => {
  cleanup();
});

const disposable = new DisposableDelegate(() => {
  cleanup();
});
disposable.dispose();

class Owner {
  private _disposables = new DisposableSet();
}

Options

ownershipFunctionNames

Function or method names that take ownership of disposable arguments. The default list is add, addCell, addFactory, addItem, addModelFactory, addSibling, addMenu, addWidget, addWidgetFactory, insertItem, insertWidget, and registerStatusItem. If provided, this list replaces the default. Set this option to [] to require stricter typed ownership checks.

{
  "jupyter/require-disposable-ownership": [
    "warn",
    {
      "ownershipFunctionNames": ["ownDisposable", "registerDisposable"]
    }
  ]
}