Mercurius federation subscriptions test

Gateway 'api-gateway' and federated service 'auth' is based on fastify-gql (mercurius). Federated schema is builded using build-federated-schema script example. Type-graphql is used for typescript schema and resolvers.

To run:

1. git clone
2. docker-compose up -d
3. yarn install && yarn build && yarn start

To test the subscriptions in gateway:

1. go http://localhost:8090/playground

2. init subscription: subscription { simpleSubscription { id message date } }

3. init mutation: mutation { simpleMutation(message:"1") }

After subscription is closed you can do mutation again, the resolver is still receiving a message from pubsub.