Exports in package.json

Hello. I work on a team dedicated to improving user experience

when working with money. We deliver the front-end in npm packages.



At some point, I ran into problems that led me to use a

field exports



inpackage.json

Problem # 1

Packages can export functions with the same name but do different things. Let's take 2 state managers as an example: Reatom and Effector.



They export the function createStore



. If you try to export them from one package (let's call it vendors



), you get the following picture:

// @some/vendors/index.ts

export { createStore } from '@reatom/core';
export { createStore } from 'effector';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

There is a conflict of names. This kind of code just won't work.

This can be avoided by as



:

// @some/vendors/index.ts

export { createStore as reatomCreateStore } from '@reatom/core';
export { createStore as effectorCreateStore } from 'effector';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

Looks, frankly, lousy. In an amicable way, each re-export must be written through as



to maintain consistency. This makes DX worse for me.



I started looking for a solution that would avoid both the name conflict and the need to write as



. How could it look ... For example, like this:

// @some/vendors/reatom.ts

export { createStore } from 'reatom';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

// @some/vendors/effector.ts

export { createStore } from 'effector';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

In two different files, we write regular exports and import the required implementation createStore



:

// someFile.ts

import { createStore } from 'vendors/effector';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

#2

vendors



, , -, - . , Runtypes.

exports



, :

// someFile.ts

import { createStore, Dictionary, createEvent, Record } from 'vendors';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

- . , - :

// someFile.ts

import { createStore, createEvent } from 'vendors/effector';
import { Dictionary, Record } from 'vendors/runtypes';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

. .

// someFile.ts

import { createStore, createEvent } from 'vendors/state';
import { Dictionary, Record } from 'vendors/contract';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, exports



package.json

// package.json

"exports": {
  "./contract": "./build/contract.js",
  "./state": "./build/state.js",
  "./package.json": "./package.json"
}
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, . TypeScript, .



package.json types



, , . . contract



, state



. ?



typesVersions



package.json

// package.json

"typesVersions": {
  "*": {
    "contract": ["build/contract.d.ts"],
    "state": ["build/state.d.ts"]
  }
}
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, exports



, d.ts



, .

exports



vendors



. DX.



, Effector :

import { createEvent } from 'effector';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

:

import { createEvent } from 'effector/compat';
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

exports



.

.

!