Spin up a test server on a random port

httpservertesttemplate.js

describe('my server', function () {
    let serverUrl;

    beforeEach(function () => {
        const server = http.createServer((req, res) => {
            // ...
        }).listen(0);
        const serverAddress = server.address();
        const serverHostname = serverAddress.address === '::' ? 'localhost' : serverAddress.address;
        serverUrl = 'http://' + serverHostname + ':' + serverAddress.port + '/';
    });

    it('should foo', function () {
        // Make request to `serverUrl` and make assertions about the response
    });
});