getListenerStats

The getListenerStats method provides a set of statistics about the listeners registered with the Checkpoints object, and is used for debugging purposes.

getListenerStats(): CheckpointsListenerStats

The CheckpointsListenerStats object contains a breakdown of the different types of listener.

The statistics are only populated in a debug build: production builds return an empty object. The method is intended to be used during development to ensure your application is not leaking listener registrations, for example.

const store = createStore();
const checkpoints = createCheckpoints(store);
checkpoints.addCheckpointIdsListener(() => {
  console.log('Checkpoint Ids changed');
});
checkpoints.addCheckpointListener(null, () => {
  console.log('Checkpoint label changed');
});

console.log(checkpoints.getListenerStats());
// -> {checkpointIds: 1, checkpoint: 1}