Using Grester to simplify JUnit tests for Java applications

Grester is an Apache Maven wrapper for Jester that checks for code that has not been written in a test-driven fashion

Written by Ivan Moore, Jester is an excellent tool for testing unit tests written by programmers and developers. The tool is based on the assumption that many areas of the code contain conditional statements, circular statements, and case statements, and that in some areas of code, the cyclomatic complexity of the class (cyclomatic complexity) suddenly increases because there are many execution paths. Jester is primarily concerned with code like this. To run it, however, you must use a well-formed classpath that points to each resource.

Grester is the Apache Maven wrapper for Jester, which eases the hassle of constructing Java™ classpath from project dependencies so that you can use Jester to test execution points more easily. Grester also enhances some of the benefits of using MAVEN, which is at the heart of its infrastructure. Jester is particularly useful when additional checks are performed on code that is not written in a test-driven fashion. Such code can be legacy code in legacy applications, or even the most recently written code, which developers believe is more difficult to use with Agile test-driven methods to guide building high-quality code.

In fact, you can use Grester to break the restrictions of writing code using a test-driven approach. In my experience, scope spread (scope creep) and code that might miss or bypass the actual business functions will increase the number of errors and malicious code (quickly handle BLOB inversion, even in very small snippets, without being a single, unmanageable module or set of modules).

This article does not discuss the technical details of interpreting Jester output and describing exactly how Jester works. This article aims to explore the use of the Maven plug-in wrapper around Jester.

Get Grester

The infrastructure required to run Grester is minimal: You can build and use Grester only with Maven. Grester is written in groovy, and groovy is a dynamic language whose syntax is similar to Java and has the advantages of languages such as Python and Ruby. Grester is essentially just another Maven plug-in for fast-running Jester tools, so the real power of Grester comes from Jester. In this article, the Jester V1.37 and Grester V0.3 Alpha distributions are used in combination.

Jester: Why?

If all project Java Archive (JAR) dependencies are in one place, it is not possible to run Jester directly than to refer to a single path in a Java classpath entry. However, when the dependencies are spread across the file system, the configuration problems that run every Jester are complex and annoying, especially if the dependencies change over time. Using Maven will significantly simplify this process.

Jester runs in every instance outside of the Maven project build configuration. So, what's special about Grester? The answer lies in how Maven organizes its dependencies. This "arrangement" is very efficient, and Maven tries not only to standardize the way Java (or Groovy) JAR and Web Archive (WAR) is found, but also to try to standardize the way it is saved.

Linux and UNIX user attention
The Grester file size is very small, and after decompression, you can safely delete the current compressed archive. Here's how simple it is to use Cygwin in a Windows computer to illustrate how easy it is to decompress-even in a simulated Linux environment. However, it is not recommended to test on Linux or UNIX systems with a version earlier than grester 0.3 because, although the Windows Alpha version is very stable, some operating system features are missing. However, in all versions, the Jester V1.37 is used.

If you are unfamiliar with Maven, use the concept of a system library. There is a default local system library located in the $USER _home\.m2\repository, and a remote system library that is configured in Pom.xml or settings.xml files located in the $MAVEN _home/conf.

Install Grester

After you get the tar compressed resources (. tar files and tar.gz files for UNIX® and linux®) or microsoft®windows®zip files, unzip them. There are a number of ways to do this: here I use the Cygwin utility in Windows.

Figure 1. Extract Grester using the Cygwin utility in Windows