module.exports vs exports in Node.js

Question

I\'ve found the following contract in a Node.js module:

module.exports = exports = nano = function database_module(cfg) {...}

I wonder what

Answer 1

JavaScript passes objects by copy of a reference

It's a subtle difference to do with the way objects are passed by reference in JavaScript.

exports and module.exports both point to the same object. exports is a variable and module.exports is an attribute of the module object.

Say I write something like this:

exports = {a:1};
module.exports = {b:12};

exports and module.exports now point to different objects. Modifying exports no longer modifies module.exports.

When the import function inspects module.exports it gets {b:12}