Typescript express middleware
The following should work fine i.e. use fat arrow for DoSomething not DoSomethingPrivate:
import * as express from 'express';var app = express();class Test { constructor() { } // important: DoSomething = (req:express.Request, res:express.Response, next:express.NextFunction) => { this.DoSomeThingPrivate(); } private DoSomeThingPrivate() :void { }}var test = new Test();app.use(test.DoSomething);Note: You should not need to use bind. Also https://www.youtube.com/watch?v=KDrWLMUY0R0&hd=1
You've passed a reference just to the function itself. The function's instance will be global. You need to bind the function to the instance of test.
app.use(test.DoSomething.bind(test));