System Rules is a collection of JUnit rules for testing code which uses java.lang.System.

System Lambda is an alternative to System Rules that leverages the possibilities of Java 8. It is independent of the test framework. You can use it for example as a replacement for System Rules in JUnit Jupiter and TestNG.

System Rules is available from Maven Central.

<dependency>
  <groupId>com.github.stefanbirkner</groupId>
  <artifactId>system-rules</artifactId>
  <version>1.19.0</version>
</dependency>

Please don't forget to add the scope test if you're using System Rules for tests only.

System Rules' documentation is stored in the gh-pages branch and is available online at http://stefanbirkner.github.io/system-rules/index.html

You have three options if you have a feature request, found a bug or simply have a question about System Rules.

• Write an issue.
• Create a pull request. (See Understanding the GitHub Flow)
• Write a mail to [email protected]

System Rules is build with Maven. If you want to contribute code than

• Please write a test for your change.
• Ensure that you didn't break the build by running mvnw test.
• Fork the repo and create a pull request. (See Understanding the GitHub Flow)

The basic coding style is described in the EditorConfig file .editorconfig.

System Rules supports Travis CI (Linux) and AppVeyor (Windows) for continuous integration. Your pull request will be automatically build by both CI servers. On Travis CI we build your pull request with OpenJDK 6 and run test with different JDKs (Java 6 to 10).

• Select a new version according to the Semantic Versioning 2.0.0 Standard.
• Set the new version in pom.xml and in the Installation section of this readme.
• Commit the modified pom.xml and README.md.
• Run mvnw clean deploy with JDK 6 or 7.
• Add a tag for the release: git tag system-rules-X.X.X