l.js
  const { gToolbox, gHeapAnalysesClient } = window;

  root = document.querySelector("#app");
  store = Store();
  const app = createElement(App, {
    toolbox: gToolbox,
    commands,
    heapWorker: gHeapAnalysesClient,
  });
  const provider = createElement(Provider, { store }, app);
  ReactDOM.render(provider, root);
  unsubscribe = store.subscribe(onStateChange);

  // Exposed for tests.
  window.gStore = store;
};

const updateFront = front => {
  store.dispatch(updateMemoryFront(front));
};

const destroy = function () {
  // Prevents any further action from being dispatched
  store.dispatch(START_IGNORE_ACTION);

  const ok = ReactDOM.unmountComponentAtNode(root);
  assert(
    ok,
    "Should successfully unmount the memory tool's top level React component"
  );

  unsubscribe();
};

// Current state
let isHighlighted;

/**
 * Fired on any state change, currently only handles toggling
 * the highlighting of the tool when recording allocations.
 */
function onStateChange() {
  const { gToolbox } = window;

  const isRecording = store.getState().allocations.recording;
  if (isRecording === isHighlighted) {
    return;
  }

  if (isRecording) {
    gToolbox.highlightTool("memory");
  } else {
    gToolbox.unhighlightTool("memory");
  }

  isHighlighted = isRecording;
}

module.exports = { initialize, updateFront, destroy };
PK