Function decorator

test/decorator.test.js:588–596

(instance, opts, done)

  const fastify = Fastify()

  const decorator = function (instance, opts, done) {
    instance.decorate('decoratorAddSchema', function (whereAddTheSchema) {
      instance.addSchema({
        $id: 'schema',
        type: 'string'
      })
    })
    done()
  }

  fastify.register(fp(decorator))