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typescriptmodulecommonjs

confused about typescript modules

i have module file: 

// class.ts
export default class MyClass {}
module.exports = MyClass // for importing in node.js withous require('./module').default

when i import this in node.js, it works: 

// class-user.js
const Class = require('./class')
const a = new Class() // alright

but when i try to use this in typescript: 

// class-user.ts
import Class from './class'
// class === undefined

// but

import * as Class from './class'
const a = new Class()
// a is instance of Class, but
// [ts] Cannot use 'new' with an expression whose type lacks a call or construct signature.
Solution

  • Your problem is here:

    module.exports = MyClass

    It overwrites your default export.

    Use this code for class.ts:

    // class.ts
class MyClass {}
export = MyClass

    Then, to use it:

    // class-user.ts
import * as Class from './class'
const a = new Class()

    Notice: You can't use default and export = on the same module.