Arquillian, JBoss’ foray into providing in-container testing for Java EE projects, could be used to give Java EE container developers the ability to test their containers using a set of tests based on expected Java EE behavior. Such tests will enable developers of the next generation of application servers to not only run unit and integration tests on their contains but can be used to ensure compliance with the Java EE spec. It would be especially useful for integration testing where different frameworks are developed in isolation leading to integration issues when it gets out to the public.

In an ideal world, the Java EE vendors could get together and share a common open set of tests to ensure that they are all following the same rules of the spec, almost like an informal TCK. Having such a set of tests would ensure higher quality application servers are turned out in a faster time. Going from Java EE 5 to Java EE 6 was quite a big leap, I don’t think anyone is expecting as much of a leap from Java EE 6 to 7 or 8, so now would be a good time to consider those options.

This is one of those things where everybody gains. All the vendors get the benefits of product improvement due to the unit tests and they all get the benefits of Java EE having a better reputation as a solid, portable framework with more timely releases.

From http://www.andygibson.net/blog/article/can-arquillian-boost-java-ee-container-quality/