@virtualstate/app-history/src/event-target/descriptor.ts

Native JavaScript [app-history](https://github.com/WICG/app-history) implementation

import {EventCallback} from "./callback"

export const EventDescriptorSymbol = Symbol.for("@opennetwork/environment/events/descriptor");

export interface EventDescriptor {
    [EventDescriptorSymbol]: true;
    type: string | symbol
    callback: EventCallback
    once?: boolean
}