What could be causing the TypeScript class property to be undefined?

Below is the code snippet I am working with:

class FeedbackController {

  public homePage(req, res){
    this.test();
    res.send('Welcome to feedback service');
  }
 
  private test(){
    console.log('test called');
  }
}

export default new FeedbackController();

This is how I am calling it in my project:

import FeedbackController from '../controller/feedbackController';

    const routes = (app) => {
        app.route('/')
        .get(FeedbackController.homePage);

    };

    export default routes;

However, I encountered the following error:

TypeError: Cannot read property 'test' of undefined

I'm unsure about what is causing this issue. Can someone help me figure out what's wrong?

Answer №1

This is more of a JavaScript issue than TypeScript. To understand how this functions in JS, refer to this link.

To solve the problem, you can replace routes with:

.get((req, res) => FeedbackController.homePage(req, res))

or

.get(FeedbackController.homePage.bind(FeedbackController))

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