RxAutoDispose.ts

export function RxAutoDispose<T extends React.ComponentClass<any>>(target: T): T {
    target.prototype.disposer = new Rx.Subscription()

    const originalMount = target.prototype.componentDidMount
    Object.defineProperty(target.prototype, "componentDidMount", {
        value: function() {
            console.log("componentDidMount")
            return originalMount.apply(this, arguments)
        }
    })

    const originalUnmount = target.prototype.componentWillUnmount
    Object.defineProperty(target.prototype, "componentWillUnmount", {
        value: function() {
            console.log("componentWillUnmount")
            target.prototype.disposer.unsubscribe()
            target.prototype.disposer = new Rx.Subscription()
            return originalUnmount.apply(this, arguments)
        }
    })
 
    return target
}

Sample.tsx

@RxAutoDispose
export class BookGridCell extends Component<Props, State> {
  ...
}