ES6 module syntax: is it possible to `export * as Name from ...`?

Question

See question title. I found a great reference for the forms of export available, but I have not seen what I'm looking for.

Is it possible to do something like the following?

// file: constants.js
export const SomeConstant1 = 'yay';
export const SomeConstant2 = 'yayayaya';

// file: index.js
export * as Constants from './constants.js';

I.e. this would provide a named export Constants inside of index.js containing all of the named exports from constants.js.

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This answer seems to indicate it's not possible in TypeScript; is the same true for pure JavaScript?

(This example is a bit contrived; in reality I'm trying to have a prop-types.js module that uses named exports for internal use within the React package, but also exports the prop type definitions under PropTypes for external consumption. I tried to simplify for the sake of the question.)

Answer 1

No, it's not allowed in JS either, however there is a proposal to add it. For now, just use the two-step process with importing into a local variable and exporting that:

// file: constants.js
export const SomeConstant1 = 'yay';
export const SomeConstant2 = 'yayayaya';

// file: index.js
import * as Constants from './constants.js';
export {Constants};

Answer 2

Today in 2019, it is now possible.

export * as name1 from …;

Answer 3

The proposal for this spec has merged to ecma262. If you're looking for this functionality in an environment that is running a previous JS, there's a babel plugin for it! After configuring the plugin (or if you're using ecma262 or later), you are able to run the JS in your question:

// file: constants.js
export const SomeConstant1 = 'yay';
export const SomeConstant2 = 'yayayaya';

// file: index.js
export * as Constants from './constants.js';

// file: component.js
import { Constants } from './index.js';

const newVar = Constants.SomeConstant1; // 'yay'