Definition of the default export function type

Question

Definition of the default export function type

Trying to create a typings definition for the pouch-redux-middleware library, which consists of a single function:

import PouchMiddleware from 'pouch-redux-middleware'

PouchMiddleware({...})

This is the typings definition that has been attempted:

interface PouchMiddleware {
  (a: any): any;
}

declare var PouchMiddleware: PouchMiddleware;

declare module "pouch-redux-middleware" {
  export = PouchMiddleware;
}

However, an error occurs stating:

Module '"pouch-redux-middleware"' has no default export.

What would be the correct way to declare this?

typescript

Answer 1

Answer №1

When it comes to transpiling to commonjs modules, a simple way to adjust the definition file is by:

declare function PouchMiddleware(a: any): any;

declare module "pouch-redux-middleware" {
    export = PouchMiddleware;
}

Then you can import it using this syntax:

import PouchMiddleware = require("pouch-redux-middleware");

It's not ideal, but there might be a better solution out there.

My previous answer may only apply when targeting ES6 and setting the module as "ES2015":

In order for it to work, you'll have to compile with --allowSyntheticDefaultImports, and then adjust the interface in the definition file to a function:
declare function PouchMiddleware(a: any): any;

declare module "pouch-redux-middleware" {
    export = PouchMiddleware;
}
A similar situation arises with the react library. Learn more here...

Answer 2

When it comes to transpiling to commonjs modules, a simple way to adjust the definition file is by:

declare function PouchMiddleware(a: any): any;

declare module "pouch-redux-middleware" {
    export = PouchMiddleware;
}

Then you can import it using this syntax:

import PouchMiddleware = require("pouch-redux-middleware");

It's not ideal, but there might be a better solution out there.

My previous answer may only apply when targeting ES6 and setting the module as "ES2015":

In order for it to work, you'll have to compile with --allowSyntheticDefaultImports, and then adjust the interface in the definition file to a function:
declare function PouchMiddleware(a: any): any;

declare module "pouch-redux-middleware" {
    export = PouchMiddleware;
}
A similar situation arises with the react library. Learn more here...

Answer 3

Answer №2

Typically, you can export and import a class using the following format:


module custom-module {
    export class customClass {

    }
}

To utilize the exported class, simply write:


import {customClass} from 'CustomFileName'

Best regards,

John

Answer 4

Typically, you can export and import a class using the following format:


module custom-module {
    export class customClass {

    }
}

To utilize the exported class, simply write:


import {customClass} from 'CustomFileName'

Best regards,

John

Definition of the default export function type

Answer №1

Answer №2

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