Ggtcf

Consider having following files:

index.js

(async () => 
 const iife = await require('./asyncIIFE');
 console.log('[index.js]', iife);

 require('./module');
)();

asyncIIFE.js

module.exports = (async () => 'Testing async IIFE')();

module.js

const iife = require('./asyncIIFE');

(() => 
 // Should print Testing async IIFE
 console.log('[module.js]', iife); // Promise

 iife.then(text => console.log('[module.js]', text)); // Testing async IIFE
)();

The main idea is to calculate all the values in entry point (index.js) and then use them without recalculating in other files. The first require('asyncIIFE') should be asynchronous, next should immediately return value.

It should look like:

1. Require all async modules in index.js and await for results




2. All further requires of the same async modules in other files (eg.
   module.js) should immediately return value without need for await/.then()

Code output:

[index.js] Testing async IIFE
[module.js] Promise 'Testing async IIFE' 
[module.js] Testing async IIFE

In short, I want to get rid of that promise in module.js file and get cached value. How can I achieve that?

While you are importing async.js in your module.js file, you aren't resolving the function.

In module.js

const iife = require('./async');

(async () => 
 // Should print Testing async IIFE
 console.log('[module.js]', await iife); // Promise
 // Notice how I added the await keyword, that's there to resolve the promise
 // Function has also changed to asynchronous to use await.

 iife.then(text => console.log('[module.js]', text)); // Testing async IIFE
)();

Basically, you aren't resolving the file you imported, and since the file returns a promise, your console logs a promise.

index.js

(async () => 
 const iife = await require('./async');
 console.log('[index.js]', iife);

 require('./module');
)();

async.js

module.exports = (async () => 'Testing async IIFE')();

module.js

(async () => 
 const iife = await require('./async');
 console.log('[index.js]', iife);

 require('./module');
)();

Btw, I changed the filenames a bit. Hope that doesn't affect anything.