I can't use Mutex library

Question

I have nodejs app - version 10 and i installed Mutex library

https://www.npmjs.com/package/async-mutex

Following their instructions on npmjs i installed the npm package and tried to require

npm i async-mutex
var Mutex = require('async-mutex').Mutex;

after that when i start with their example:

mutex
    .acquire()
    .then(function(release) {
        // ...
    });

i get

mutex is not defined ERROR

How can i solve this problem ? The npm packages is properly installed and i tried the following:

var mutex = require('async-mutex').Mutex

then i get mutex.acquire is not a function error

Answer 1

You are missing ONE IMPORTANT part in their documentation:

const mutex = new Mutex();

So you need to do:

var Mutex = require('async-mutex').Mutex;
var mutex = new Mutex();

Now you can use mutex.acquire() . Note: NOT Mutex.acquire()