Why won't nock match url?

If I do:

nock('http://localhost:3000').get('/test').reply(200);

And then try:

fetch('http://localhost:3000').then(console.log);

I get a "No match for request" error message.

The only way I can get this to work is by using a catch-all regex:

nock(/./).get('/test').reply(200);

Based on these instructions, it really seems as though the first should work as well.

Any idea what I'm missing?