The following paragraphs will introduce the essentials of how to apply Hamcrest matchers to test assertion and show you how to write your own predicate extensions.
Hamcrest, [HAMJAV], aims to provide an API to create flexible expressions of intent. The utility offers nestable predicates called Matchers to do so. These allow writing complex verification conditions in a way which many developers consider easier to read than Boolean operator expressions.
Test assertion is supported by the MatcherAssert class. It offers the assertThat(T, Matcher<? super T>) static helper method. The first argument passed is the object to verify. The second is an appropriate predicate used to evaluate the first one:
assertThat( item.getTimeStamp(), equalTo( 10L ) );
Matcher implementations provide static factory methods for instantiation (above IsEqual.equalTo(T)). The intention is to mimic the flow of a natural language. This is...