Ways to incorporate extension methods through a "barrel file" - how to do it?

When attempting to define extension methods in separate files and import them through a barrel file, the methods don't seem to be added to the prototype.

The following approach works:

import './rxjs-extensions/my-observable-extension-1';
import './rxjs-extensions/my-observable-extension-2';

//...

obs
    .extension1()
    .extension2();

However, if a barrel file is created:

// rxjs-extensions/index.ts

export * from './my-observable-extension-1';
export * from './my-observable-extension-2';

and then only the barrel file is imported

import './rxjs-extensions';

//...

obs
    .extension1()
    .extension2();

A run-time error occurs stating that extension1 is not a function.

What could be the issue here? Is it feasible to use a barrel file for importing extension methods in this manner?

Answer №1

After some experimentation and tinkering...

It turns out that the barrel file should not use export * from... in this scenario because the individual files are not actually exporting anything. Instead, it should simply import the individual files.

// rxjs-extensions/index.ts
import './my-observable-extension-1';
import './my-observable-extension-2';

By following this approach, importing the barrel functions smoothly.

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