[RxJS] sample

Emits the most recently emitted value from the source Observable whenever another Observable, the notifier, emits.

 sample<T>(notifier: Observable<any>): MonoTypeOperatorFunction<T>

It's like sampleTime, but samples whenever the notifier Observable emits something.

import { StrictMode } from "react";
import ReactDOM from "react-dom";
import { fromEvent, mapTo, merge, sample } from "rxjs";

import App from "./App";

merge(
  fromEvent(document, "mousedown").pipe(mapTo(false)),
  fromEvent(document, "mousemove").pipe(mapTo(true))
)
  .pipe(
    sample(fromEvent(document, "mouseup"))
  ).subscribe(isDragging => {
    console.log("Were you dragging", isDragging)
  })
const rootElement = document.getElementById("root");
ReactDOM.render(
  <StrictMode>
    <App />
  </StrictMode>,
  rootElement
);