express.Router() is undefined after converting to TypeScript

Question

I am converting my express nodejs project from JS to TypeScript. I renamed the file extension, changed var to import for "require()" , however there is one thing that is working and is undefined, express.Router().

import express = require('express');
var router = express.Router(); // Undefined
import mongoose = require('mongoose');

What should I do to resolve it?!

Answer 1

First, in you project directory, you need to install typings

npm install -g typings

Then, install the typing destination for expressJS

typings install express --ambient --save

This will create a typings.json and should fix your problem