Go-MediatR VS testcontainers-go

Some of the features: - ✅ Using Vertical Slice Architecture as a high level architecture - ✅ Using Event Driven Architecture on top of RabbitMQ Message Broker with a custom [Event Bus](pkg/messaging/bus/) - ✅ Using Event Sourcing in Audit Based services like [Orders Service](services/orders/) - ✅ Using CQRS Pattern and Mediator Patternon top of Go-MediatR library - ✅ Using Dependency Injection and Inversion of Controlon top of uber-go/fx library - ✅ Using RESTFul api with Echo framework and using swagger with swaggo/swag library - ✅ Using Postgres and EventStoreDB to write databases with fully supports transactions(ACID) - ✅ Using MongoDB and Elastic Search for read databases (NOSQL) - ✅ Using OpenTelemetry for collection Distributed Tracing with using Jaeger and Zipkin - ✅ Using OpenTelemetry for collection Metrics with using Prometheus and Grafana - ✅ Using Unit Test for testing small units with mocking dependent classes and using Mockery for mocking dependencies - ✅ Using End2End Test and Integration Test for testing features with all of their real dependeinces using docker containers (cleanup tests) and testcontainers-go library

There are some mediator-like libraries like https://github.com/mehdihadeli/Go-MediatR or https://github.com/erni27/mob but they are not used widely like for example their C# sibling https://github.com/jbogard/MediatR. Also, neither I see custom implementations of mediator in many projects.

Let's first look at the original version of the test, in this case, an end-to-end, using testcontainers.

It supports multiple languages (including Go!) and databases (also messaging infrastructure etc.) - All you need is Docker. Testcontainers for Go makes it simple to programmatically create and clean up container-based dependencies for automated integration/smoke tests. You can define test dependencies as code, run tests and delete the containers once done.

Testcontainers Go Documentation

Some of the features: - ✅ Using Vertical Slice Architecture as a high level architecture - ✅ Using Event Driven Architecture on top of RabbitMQ Message Broker with a custom [Event Bus](pkg/messaging/bus/) - ✅ Using Event Sourcing in Audit Based services like [Orders Service](services/orders/) - ✅ Using CQRS Pattern and Mediator Patternon top of Go-MediatR library - ✅ Using Dependency Injection and Inversion of Controlon top of uber-go/fx library - ✅ Using RESTFul api with Echo framework and using swagger with swaggo/swag library - ✅ Using Postgres and EventStoreDB to write databases with fully supports transactions(ACID) - ✅ Using MongoDB and Elastic Search for read databases (NOSQL) - ✅ Using OpenTelemetry for collection Distributed Tracing with using Jaeger and Zipkin - ✅ Using OpenTelemetry for collection Metrics with using Prometheus and Grafana - ✅ Using Unit Test for testing small units with mocking dependent classes and using Mockery for mocking dependencies - ✅ Using End2End Test and Integration Test for testing features with all of their real dependeinces using docker containers (cleanup tests) and testcontainers-go library

For example, you could take a look at this open-source project that helps you spawn docker containers as part of your test setup enabling you to execute queries to a local database.

Using something like TestContainers to spin up a DB for testing has been my best experience. Any mocks leave too much room for error imo

I highly recommend testcontainers for this.

The next block in .gitlab-ci.yml is the services block. Since our tests use testcontainers package and we're pushing a docker container onto Dockerhub, we will need to specify a services block next. Services will enable our pipeline to leverage Docker-in-Docker DinD.