Annotation Matchers
About
This is a helper library to easily unit test the usage of Annotations
Why? (Method to the Madness)
So you may be wondering, what's the point of this library?
In my experience in both QA and Development, I've noticed that configuration and not implementation is the culprit of many problems found in production. Obviously, there are other things to consider when trying to better understanding how bugs are introduced. For example, incorrect documentation and lack of proper requirements can be to blame. And of course, code that doesn't correctly implement the expected functionality.
Of these problems, its obvious that more/ better unit tests that verify that the implementation actually implemented the feature would prevent some bugs. And spending more time reviewing documentation and discussing requirements might prevent some bugs too.
But what about configuration?
Sometimes you may have some highly configurable component, or use some feature that is parameterized. And even though the feature works, or is expected to work based on some method contract, it doesn't! Why? Usually it's because someone used it wrong, because someone forgot to properly configure it.
One aspect of "configuration", at least in Java, are annotations. And lately, I have found myself doing a lot of Spring Boot development. And a lot of it (if done right), involves annotations. I end up having to write integration tests confirming that I've properly annotated some method or parameter that enables some Spring feature. Based on my experience with Spring, unless I do something wrong, it kinda just "works". So I thought instead of having to write these sort of tests why not just double check that I am using Spring correctly? <insert mind blown gif here>
This library is intended to enable lazy folks like me to check for human error and not check implementation details or frameworks that are already tested.
Dependencies
- org.hamcrest.hamcrest-core
- com.nycjv321.reflection
- Java 8
Example Usage
See the unit tests. If you're too impatient (shame on you), see below:
import static has;
import static org.hamcrest.MatcherAssert.assertThat;
// ...
// (This test only works on Java 8 + "-parameters" javac argument)
// Assert that the TestClass#convert(String[][] arguments)
// "arguments" criterion has the WebParam annotation.
Criterion criterion = Receiver
.of(TestClass.class)
.on("convert", String[][].class)
.criterion("arguments");
assertThat(
criterion,
has(WebParam.class)
);
// additional tests here