Use AssertJ to improve your test code readability, maintenance of tests easier

AssertJ core is a Java library that provides a fluent interface for writing assertions.It provides assertions for JDK standard types and can be used with JUnit, TestNG or any other test framework.

Key Features :

• AssertJ provides a rich set of assertions, truly helpful error messages, improves test code readability and is designed to be super easy to use within your favorite IDE.
• AssertJ gives readable error messages, soft assertions, and improved collections and exception support.
• You can easily write assertions for your own classes, which will make your test assertions reflect the domain
• Basic tips :
  • Java 8 assertions
  • IDE configuration to directly get assertThat in code completion
  • Describe your assertion using as(String description, Object… args)
  • Exception assertions guide
  • Using String assertions on the content of a file

  Iterable and arrays assertions :

  • Combining filtering and assertions on iterables or arrays
  • Assertions on extracted properties/fields of iterable/array elements
  • Flat(map) extracting
  • Assertions on results of a method call on iterable/array elements
• Gather all errors message with soft assertions
• Using a custom comparison strategy in assertions
• Field by field comparisons
• Using a custom representation in assertions
• Extending assertions with conditions
• Creating assertions for your domain
• AssertJ provides assertions for popular libraries like Guava,Joda Time & Neo4J

Get started with one minute starting guide

If you want to convert your JUnit assertions to AssertJ,here it is!

Like this post? Don’t forget to share it!