Testing

Maintaining architecture rules and constraints for a specific software project or an application is not easy as textual documentation is easily forgotten after a while and hard to verify. ArchUnit is a testing library that allows developers and software architects to write down such rules as executable tests that may be run by the development teams and the integration servers. In the following article I will demonstrate the basic features of this library by applying rules and constraints to an existing application. ...

In our tests we often need to create a bunch of test-objects that are populated with random-data. This data needs to follow specific rules as identifiers need to be unique or must be incremented, string-properties must follow special conventions and so on. In the following short tutorial I will demonstrate how to generate such test data using the Fixture Factory library. Figure 1. Fixture Factory and JUnit...

There is a new testing framework out there called Karate that is build on top of the popular Cucumber framework. Karate makes it easy to script interactions with out web-services under test and verify the results. In addition it offers us a lot of useful features like parallelization, script/feature re-use, data-tables, JsonPath and XPath support, gherkin syntax, switchable staging-configurations and many others. In the following tutorial we’ll be writing different scenarios and features for a real-world RESTful web-service to demonstrate some of its features. ...

When building up search engines, indexing tons of data into a schema-less, distributed data store, Elasticsearch has always been a favourite tool of mine. In addition to its core features, it also offers tools and documentation for us developers when we need to write integration tests for our Elasticsearch powered Java applications. In the following tutorial I’d like to demonstrate how to implement a small sample application using Elasticsearch under the hood and how to write integration-tests with these tools for this application afterwards. ...

Writing tests not only to verify the behaviour of a web site but also the correctness of its layout especially for responsive websites is not always easy. Luckily the Galen Framework eases the task of writing layout tests for us, offering a specialized domain-specific-language to write layout-specifications, it integrates well with Selenium Grid, Sauce Labs or BrowserStack, it offers an easy way to deal with different browser sizes and responsive designs and it generates nice, detailed test reports. ...

I have written about other performance testing tools for web applications before. Nevertheless I’d like to demonstrate a library for load testing web applications named Gatling in combination with the build tool Maven. Gatling offers a nice Scala DSL, high performance using Akka, Netty and asynchronous IO and plug-ins for all modern build tools. In the following tutorial I’m going to show how to record simulations using an HTTP proxy, rewriting simulations in Scala and running and reporting simulations with Maven. ...

Generating test suites for existing code allows us to verify the behaviour of an application before we’re making changes to its code base or for regression testing. In the following short tutorial I’d like to demonstrate how to derive test suites from an existing Java application using EvoSuite and the EvoSuite Maven plug-in. EvoSuite offers some nice features like running in a sandbox to avoid dangerous operations, virtual file-system and network and optimizing of different coverage criteria. ...

When writing tests for our software components sometimes we need to mock external services based on the HTTP protocol, might it be a RESTful web-service, an XML-RPC call or a simple GET request to some web-server. In the following short tutorial I’d like to demonstrate how to create a mock HTTP server for testing and how to bootstrap and bind it to the life-cycle of a classical build-management tool like Maven. ...

Writing tests for asynchronous applications has never been much fun as we’re always struggling with the problem how to determine state changes, handle process terminations, dealing with timeouts or failures and stuff like this. Awaitility eases this process for us offering a nice DSL, rich support for languages like Scala or Groovy and an easy-to-use syntax that’s even more fun when using it with Java 8′s lambda expressions. In the following short introduction I’d like to demonstrate writing some tests different scenarios. ...

Mutation testing makes an interesting addition to the classical test coverage metrics. They seed mutations (errors) into the code, run the project’s tests afterwards and if the tests fail, the mutation is killed – otherwise it lived and we have a possible indication of an issue with our tests. In the following short tutorial. I’d like to demonstrate how to setup mutation tests with the PIT/Pitest library and Maven and generate reports. ...