I want to make an instance of a class without importing the class first and making new afterwards.

Instead of

var mainClass = require('../dist/main'); // has "class Main { ... }"
var mainInstance = new mainClass();

I want

var mainInstance = new require('../dist/main').Main();

But something with the syntax is wrong.

var main = new require('../dist/main').Main();
                                       ^
TypeError: Class constructor Main cannot be invoked without 'new'

Is this even possible? I use a bination of TypeScript and plain JS.

I want to make an instance of a class without importing the class first and making new afterwards.

Instead of

var mainClass = require('../dist/main'); // has "class Main { ... }"
var mainInstance = new mainClass();

I want

var mainInstance = new require('../dist/main').Main();

But something with the syntax is wrong.

var main = new require('../dist/main').Main();
                                       ^
TypeError: Class constructor Main cannot be invoked without 'new'

Is this even possible? I use a bination of TypeScript and plain JS.

• javascript
• node.js
• typescript

• What's the actual syntax error you get? – erbridge Commented Jan 27, 2017 at 16:23
• @erbridge see my update – Daniel W. Commented Jan 27, 2017 at 16:25
• If you want there to only ever be one instance, you could just export an instance instead of the class, to prevent misuse. – castletheperson Commented Jan 27, 2017 at 16:28

1 Answer 1

You can use parenthesis to achieve that:

var main = new (require('../dist/main').Main)();

And if your module.exports was solely exporting a class you'd do it like following:

var main = new (require('../dist/main'))();