Building Microservices with Go

Dependency injection and mocking

To get the tests that return items from the Search handler to pass, we are going to need a data store. Whether we implement our data store in a database or a simple in-memory store we do not want to run our tests against the actual data store as we will be checking both data store and our handler. For this reason, we are going to need to manage the dependencies on our handler so that we can replace them in our tests. To do this, we are going to use a technique called dependency injection where we will pass our dependencies into our handler rather than creating them internally.

This method allows us to replace these dependencies with stubs or mocks when we are testing the handler, making it possible to control ...