import fastify, {FastifyInstance} from 'fastify'; import foo from '../../../src/plugin/foo/index'; describe('Plugin: foo', () => { let instance: FastifyInstance; beforeEach(async () => { instance = fastify(); instance.register(foo, 'some options'); await instance.ready(); }); afterEach(() => jest.restoreAllMocks()); it('should return opt', async () => { expect(instance.hoth).toBe('hoth'); }); });