Why doesn't the following `exports = { z: function() {} };` work

Question

a.js

exports = {
    z: function() {
        console.log('aZ');
    }
};

main.js

require('./a').z(); // error

Why does require('./a') return an empty object?

Answer 1

Because in your example you are overriding the exports global, and not updating it. If you replace your code with:

exports.z = function() {
    console.log('aZ');
};

it will work, because you are adding z to the actual exports object.

---

If you look at the docs, you will see:

A reference to the module.exports that is shorter to type.

---

So you can imagine this situation:

var module = {
    exports: { /* some export stuff */ }
};

var exports = module.exports;

Now if you replace exports with exports = something, you aren't actually changing module.exports.