I'm collecting the advantages and disadvantages using Groovy for JUnit and found following interesting stuffs...
- You don't need to implement inner classes which are very awful and bloat your test codes. Instead you can use closures. Using closures for writing your mock objects can make your test codes smaller and more compact!
- File operations are very easy to implement thanks to AntBuilder. How many times do you need to make some file operations (delete, mkdir, ...) within your test codes? Doing this with java.io is not fun at all. Using AntBuilder for this purpose is a good thing, since Ant is predestinated to do this job. If you think that you could do the same thing in pure Java, you will find that this takes a lot more work. Using Ant directly in Java is unfortunately not straight forward. Example: to use the unzip Ant task you need to use the Expand Java class, which is not documented properly (so you need to dig into the Java source code). In AntBuilder you just use the same structure like your Ant file: unzip!
- If you are using SpringFramework you can easily create the config files (application context) by using BeanBuilder. By using this concept you don't need to put separate XML files in your test project. Everything is integrated and centralized in your test class!
- If you are using Ant for your build environment, you can integrate the compilation of Groovy classes easily since Groovy also offers an Ant task.
- No source code formatter for Groovy: This is a real disadvantage for Groovy at the moment. If you are working in a team this could be a nightmare: reading the code with different formatting, CVS compare is difficult, ... are some examples to mention...
- The Groovy plug-ins (code completion, syntax coloring, ...) - at least for Eclipse - is still very buggy.
- You need to learn some new concepts like: closures - which is also an advantage after you understand them! Without closures you cannot implement inner classes in Groovy, which are mostly a must in writing unit tests.
A good place to start for Groovy and Testing is right here: Groovy Testing Guide.
If you have some points to add please let me know!