U.K.-based Diffblue has developed the first artificial intelligence (AI) for code solution that automates writing unit tests for Java. The company has launched Diffblue Cover and Diffblue Cover: Community Edition, a free version created for developers using IntelliJ, the most popular IDE for enterprise Java.

The technology developed by researchers from the University of Oxford is based on reinforcement learning, the same machine learning strategy that powered AlphaGo, Alphabet subsidiary DeepMind’s software program that beat the world champion player of Go.

Diffblue Cover automates the burdensome task of writing Java unit tests that could consume up as much as 20% of Java developers’ time. The program creates Java tests at speeds 10 times to 100 times faster and automatically maintains the tests as the code evolves even on applications with tens of millions of lines of code.

A developer survey conducted in 2019 revealed that software engineers, among the most expensive talent in any company, spend 20% of their time writing unit tests, which on average provided coverage for less than half of the code written, and an additional 15% of their time writing all other types of tests.

Most unit test generators create boilerplate code for tests rather than tests that compile and run. These tools guess the inputs that can be used as a starting point but developers have to finish them to get functioning tests. Diffblue Cover can create complete human-readable unit tests that are ready to run immediately.

Diffblue Cover supports Java, the most popular enterprise programming language in the Global 2000. The technology behind Diffblue Cover can also be extended to support other popular programming languages such as Python, Javascript and C#.

Both the Teams Edition and Enterprise Edition versions install in less than five minutes and provide 100% automated Java unit test writing and integrate directly into CI/CD systems. Available free by download, Diffblue Cover: Community Edition can help onboard developers realize the benefits of automating unit test writing.