Right now, in Groovy 2.2.1, the GroovyAssert class just offers a way to embed shouldFail in JUnit 4 tests. These methods are also used internally by GroovyTestCase.
This issue is about making GroovyAssert an "official" API class for supporting JUnit 4 integration by providing a bunch of static methods that can be imported, as this is the case with org.junit.Assert.
For that purpose, the class needs JavaDoc documentation and to be mentioned in the new Groovy language documentation.
Plus, we would like to move more methods from GroovyTestCase into GroovyAssert. The same way that it was done with shouldFail.
So this issue consists of writing documentation for GroovyAssert and applying some refactoring on GroovyTestCase.