Push redux-like actions to Firebase, and retrieve responses

actions.js

export const pushActionPromise = async (firebase, type, payload) => {
  // get the key for the new action about to be created
  const actionRef = firebase.database().ref('action');
  const newKey = actionRef.push().key;
  
  // push the action
  const fullPayload = {
    uid: firebase.auth().currentUser.uid,
    type,
    payload,
  };
  await actionRef.child(newKey).set(fullPayload);
  // return the key so the user can listen for a response
  return Promise.resolve(key);
}

export const getActionResponsePromise = async (firebase, key) => {
  // read action_reponse for currentUser
  const ref = `action_response/${firebase.auth().currentUser.uid}`;
  const responseRef = firebase.database().ref(ref);
  const currentResponse = await responseRef.once('value').then(val => val.val());

  // if the response for my key is already there
  // delete it from firebase and return it
  if (currentResponse && currentResponse[key]) {
    await responseRef.child(key).set(null);
    return Promise.resolve(currentResponse[key]);
  }

  // as it's not yet been written, listen for the response.
  // if it appears, delete it from firebase and return it
  let onSet = null;
  const gotValue = new Promise((resolve) => {
    onSet = responseRef.on('child_added', async (response) => {
      if (response && response.key === key) {
        if (onSet) {
          responseRef.off('child_added', onSet);
          onSet = null;
        }
        await responseRef.child(key).set(null);
        resolve(response.val());
      }
    });
  });
  
  // a 3 second time out promise
  const timedOut = new Promise((resolve, reject) => {
    setTimeout(() => {
      if (onSet) {
        responseRef.off('child_added', onSet);
        onSet = null;
      }
      reject(new Error('timed out'));
    }, 30000);
  });
  
  // set a promise race in motion to either 
  // (a) resolve with our action_response or 
  // (b) reject after 3 seconds
  return Promise.race([gotValue, timedOut]);
}

/*
// Usage

const actionKey = await actions.pushActionPromise(firebase, 'DO_THING', payload);
try {
  const response = await actions.getActionResponsePromise(firebase, actionKey);
  if (response) {
    if (response.error) {
      setCallout('error', 'I got an error response');
    } else {
      setCallout('success', 'I got a good response');
    }
  }
} catch (error) {
  setCallout('error', 'I did not get a valid response');
}

*/