How to use single class in express js?

Question

MongoDB

I have app.ts and several classes for routing
, they must use a connection to the database (mongoose), but how can I implement so that the class (service) for working with the database is passed to these classes for routing?

Answer 1

Any exported class will be a singleton.

class Service {}

export.module = new Service();

or just to be sure

class Service {}
let service = () => {
    let instance
    function init() {
        let opt = new Service()
        return opt
    }
    return {
        getInstance: function () {
            if (!instance) {
                instance = init()
            }
            return instance
        }
    }
}

module.export = service().getInstance()

Answer 2

The simplest is to attach it to the app object.
Those. so that at any time you can contact: app.db