Javascript Mutex to prevent re-entry from multiple method calls. Protect methods that modify app, localStorage or IndexedDB.

app.js

import { lock, unlock } from './mutex.js'

async function processCallsLikeQueue() {
  // stop method calls here
  await lock('processCallsLikeQueue()')
  // ...
  // code to protect from re-entry
  // i.e. prevent multiple simultaneous calls to this part of the code
  // ...
  // let next method call in
  unlock('processCallsLikeQueue()')
}

mutex.js

let promises = {}, resolvers = {}
// uid should be unique per code you protect, e.g. the method signature
export const lock = async (uid = 'default') => {
    if (promises[uid]) { // check if lock exists
        await promises[uid] // wait on lock promise
        await lock() // stack lock check after promise resolves
        return // prev methods do nothing
    }
    // there is no lock, so we'll "acquire" it here
    promises[uid] = new Promise((resolve) => resolvers[uid] = () => {
        promises[uid] = null // release
        resolve() // resolve
    })
}
export const unlock = (uid = 'default') => {
    if (resolvers[uid]) {
        resolvers[uid]()
    }
}