In this chapter, we have discussed testing strategies for a microservice. Testing a microservice requires a high level of confidence in it. In the microservice architecture, an application has many more moving parts in comparison to others.
Unit testing tests the smallest piece of a microservice to determine if its behavior is as expected. Integration testing tests external dependencies and their communication methods between components, either externally or internally. Component testing verifies a microservice behavior in isolation from any external dependencies, whereas contract testing tests interactions at the boundary of an external service. End-to-end testing verifies the whole system, and this should ultimately meet the expected business goal.
In Chapter 8, Performance Testing of Microservices, we'll discuss the microservice approach to designing performance testing, and we'll also look at load testing tools for microservice testing, including Jmeter, the Ready API, and Gatling.