index.js

'use strict';

// The whole app is a hapi plugin

module.exports = function (server, options, next) {

    server.route({
        method: 'GET',
        path: '/add/{a}/{b}',
        handler: function (request, reply) {

            const { a, b } = request.params;

            server.methods.sum(a, b, (err, res) => {        // this method doesn't exist until plugins are registered

                if (err) {
                    return reply(err);
                }

                return reply(res);
            });
        }
    });

    server.register(require('./plugin'), next);
};

module.exports.attributes = { name: 'app', version: '1.0.0' };

plugin.js

'use strict';

// An example of a plugin that takes some time to initialize

module.exports = function (server, option, next) {

    setTimeout(() => {

        const add = (a, b, next2) => next2(null, Number(a) + Number(b));
        server.method('sum', add);

        return next();
    }, 1000);
};

module.exports.attributes = { name: 'plugin', version: '1.0.0' };

test.js

'use strict';

const Code = require('code');
const Hapi = require('hapi');
const Lab = require('lab');

const expect = Code.expect;
const lab = exports.lab = Lab.script();
const it = lab.it;

const App = require('.');

const getServer = function (onCleanup, next) {

    const server = new Hapi.Server();
    server.connection();

    onCleanup((callback) => {

        server.stop(callback);
    });

    server.register(App, (err) => {

        expect(err).to.not.exist();

        server.initialize((err) => {

            expect(err).to.not.exist();

            return next(server);
        });
    });
};

it('can add 1 + 5', (done, onCleanup) => {

    getServer(onCleanup, (server) => {

        server.inject('/add/1/5', (res) => {

            expect(res.statusCode).to.equal(200);
            expect(res.result).to.equal(6);
            done();
        });
    });
});

it('can add 7 + 8', (done, onCleanup) => {

    getServer(onCleanup, (server) => {

        server.inject('/add/7/8', (res) => {

            expect(res.statusCode).to.equal(200);
            expect(res.result).to.equal(15);
            done();
        });
    });
});