test.js

        it('assigns an ephemeral port when requested twice', function (done) {

            var server = new Hapi.Server(0);
            var server2 = new Hapi.Server(0);

            server.start(function () {

                expect(server.info.port).to.be.a('number');
                expect(server.info.port).to.be.above(0);
                server2.start(function () {

                    expect(server2.info.port).to.be.a('number');
                    expect(server2.info.port).to.be.above(0);
                    done();
                });
            });
        });

test2.js

        it('assigns an ephemeral port when requested twice', function (done) {

            var server = new Hapi.Server(0);
            var server2 = new Hapi.Server(0);

            var doneCount = 0;
            var port1, port2;

            var maybeDone = function () {
                ++doneCount;
                if (doneCount == 2) {
                    expect(port1).to.not.equal(port2);
                    done();
                }
            }

            server.start(function () {

                expect(server.info.port).to.be.a('number');
                expect(server.info.port).to.be.above(0);
                port1 = server.info.port;
                maybeDone();
            });

            server2.start(function () {

                expect(server2.info.port).to.be.a('number');
                expect(server2.info.port).to.be.above(0);
                port2 = server2.info.port;
                maybeDone();
            });
        });