Lazy exporting expensive properties

common.js

// In-expensive property
exports.foo = 'bar';

// Expensive property
var propertyName;
Object.defineProperty(exports, "propertyName", {
    get: function() { 
        return propertyName = propertyName || require('someOtherModule');
    }
});

LAZY.md

If you have a CommonJS module that exposes properties that are expensive to create (e.g. other CommonJS modules or some external resource), you can load them lazy using Object.defineProperty().