Disable loading constants module

[damianstasik]

This PR lets you implicitly import index.js file inside constants directory, where before a node module would load with native constants.

Before:

import { TEST_CONSTANT } from 'constants/index';

After:

import { TEST_CONSTANT } from 'constants';

[papermana]

Great, that's going to make some imports look that much nicer!

I'm only concerned that it might break something, e.g. make it impossible for projects that require node constants (though I don't know why they would) to work.

Maybe we could optionally control this via an ENV var? E.g. constants: FOO_BAR === 'true'.

[damianstasik]

I was about to suggest envs, after a quick search I'm pretty sure that without option to opt-out that change would break some projects. What do you think about an env named: DISABLE_NODE_CONSTANTS?

[papermana]

Sounds good, although I think that most projects might prefer opt-in instead.

[damianstasik]

Opt-in as in disabling constants or enabling them? DISABLE_NODE_CONSTANTS would not break existing projects that are using native constants for some reason.

[papermana]

I meant as in disabling them by default, and allowing projects that use them to opt-in to keep them.

[damianstasik]

@papermana Done, to bring back default behavior you can now use USE_NODE_CONSTANTS.

[papermana]

👍