Let me take you back to the days when the concept of monolithic software was all that we knew. Do you know how it must feel like working on such software? You can think of it as a large entangled mess. All the functions entwined. 

That approach of building software applications had its downside. As soon as the software grew bigger and complex, many teams had to work on it simultaneously. No one had a clear track of what the other team is doing on the same software. Moreover, they were least concerned about their action’s impact on other teams’ tasks. As a result, the entire application development process became a big mess. Not to mention the extended time it would take to build it. Furthermore, getting delayed effects and unreliable applications was a common practice. 

Luckily, an organized approach to enterprise application development came into the limelight. And that approach is microservices. As a result of which, we breathe a sigh of relief. Once we go through what microservices are, we will be talking about the main thing. That is microservices testing. 

In this blog, you will explore the following: 

  • What are microservices? 
  • How many types of microservices test are there? 
  • Tools of microservices testing
  • Challenges of microservices testing 
  • Microservices test best practices

What are microservices? 

Microservices is what unwound the functions of monolithic software. Simple, when we break down the entire software application services, these are microservices. These services represent different tasks handled by individual development teams independently. More precisely, this architecture gives us low dependency among units. Also, it offers separate modules for various functionalities. 

Now, what about communication among these units? How would these independent units compose one single software application? Is this what you are thinking right now? 

It is simple. These units stay in the loop with each other through a communication method called APIs. 

API is an application programming interface, which acts as a software intermediary. That means it makes it possible for two units/services to talk to each other. 

Like any area of your business, microservices testing is also essential. Let’s look into details about microservices testing. 

microservices testing

How many types of microservices testing are there? 

Microservices Unit Testing

Unit testing for microservices is crucial. It validates whether the microservices behave as per the expectations. For a given microservice, testers write a unit test for internal modules. 

Microservice Integration testing 

Now, how to ensure how these modules work together to form a microservice. The main goal of this testing is to detect defects in the interface. 

It is a process by which microservices testers ensure that the interaction and communication path between the modules and their remote dependencies occur without defects and interruption. Most importantly, developers should write integration testing by using existing unit test frameworks. 

Microservices component testing

Microservices component testing aims to test the single microservice in isolation. Testers do this by replacing external collaborating microservices with mock services. For simplification, there is a microservice X, which collaborates with microservice Y. 

Now, let’s say you want to do a component test on microservice X. For this, you would replace a microservice Y with a mock service. Then, this Mock microservice integrates with the microservice X. Finally, you would conduct its component test to verify its end-to-end functionality. 

By doing so, you may have a controlled testing environment and avoid complexity. 

Microservices contract testing 

What is a contract between microservices? 

It is very crucial yet easy to understand. Let’s say two microservices are collaborating, X and Y. 

In this scenario, microservice X seeks some data from a microservice Y. While microservices Y provides the data that the first microservice seeks. Therefore, it forms a contract wherein X is a consumer, and Y is a provider. Contract testing verifies how well the microservices function together. This test is crucial because unit microservice testing, integration, and component microservice testing demonstrate the behaviour of modules and individual microservice. But, this one includes the contracting action of microservices with each other. 

Microservices end-to-end testing 

End-to-end microservice testing is a method by which software applications’ workflow gets verified end-to-end or from start to end. In other terms, the goal of microservices end-to-end testing is to ascertain how well the entire system performs. Also, this type of testing microservices verifies whether the system as a whole complies with expectations. 

Microservice Performance Testing 

As soon as the individual microservice gets deployed and start integrating, performance testing becomes essential. In other words, performance microservice testing is crucial in two stages. The one is at the microservice level. And the second one is at the system level. 

Tools of microservice testing 

Following are the tools for microservice testing: 

  • Mitmproxy
  • Wilma
  • Foreplay
  • Wiremock
  • Hikaru
  • VCR
  • Mountebank
  • Gatling
  • Pact
  • Hoverfly

Challenges of testing microservices

Testing microservices although a significant aspect does pose some challenges as well. 

  • It may take an unspecified amount of time in the final deployment of software.
  • New Software testers can’t be sure 100% which testing strategy would go best and when. 
  • Here, too many development teams work independently. Thus, it becomes hard to establish a sound coordination system throughout the development process. 
  • The more microservices there are, the more complex the microservices test becomes. 
  • Developers face the issue of keeping a record of many database versions and libraries. 

Some best practices to do Microservices testing 

There are some best practices to test microservices.

  • Testers must be clear about what type of testing microservices they should conduct. Also, and on which level they need it. 
  • They need to ensure that there is an optimal level of security. Or that the software is not vulnerable to attacks. 
  • Testers must check whether the performance of services complies with expectations.
  • The performance of the entire system as a whole should also need verification.