to-mirrored-object

I often see this when people are writing constants for a Flux setup.

var keyMirror = require('key-mirror');

module.exports = keyMirror({
    USER_SIGNUP:  null
    USER_SIGNOUT: null
});

toMirroredObject saves you from having to type null values. The obvious trade off being that you have to quote the array keys. It still two less keystrokes per item.

var toMirroredObject = require('to-mirrored-object');

module.exports = toMirroredObject([
    'USER_SIGNUP',
    'USER_SIGNOUT' 
]);

=> {USER_SIGNUP: "USER_SIGNUP", 'USER_SIGNOUT: "'USER_SIGNOUT"};