A short History

The first steps on developing a datacentric testing framework began in summer 2002 after supporting a diploma thesis on Testing in a J2EE environment and its special requirements on basis of JUnit and it's extensions.
Until then I had covered good ground in using JUnit in standard application development and in testing my selfwritten service-based framework to support development of J2EE components and standard applications alike - This was done as inhouse project only.

Even in this first attempt to make developer life a little easier my major goal was to combine different very good frameworks under the hood of an easy to use framework with a rather simple API. - Why invent logging facilities when there is such an excellent logging framework as LOG4J of the Apache Jakarta project or why try to invent templating mechanisms if you can use a rock solid Velocity from Apache Jakarta project.

Why not use an existing framework then?
After a research over the web I found two frameworks that apealed to me by the basic ideas and goals they aimed - a data centric approach to unit testing.

In my opinion the major drawback in JXUnit was the complexity of usage.

  1. Define a data file - thats fine with me.
  2. Define a mapping file (in XML) to specify the mapping between xml and Java.
  3. Compile the mapping definitions by using jet another framework: Quick4 .
    As developers with a rather short schedule my colleagues didn't want to learn this extra things. They just wanted to write test data as simple and understandable as writing JUnit TestCases.

With this in mind I stumbled over JTestCase on Sourceforge.
This project used direct data structure description using Java datatypes and a mapping of XML to JUnit class structure by supporting basic object instanciations. The following example is taken from the JTestCase project version 2.1.0 on Sourceforge

<?xml version ="1.0" encoding = "UTF-8"?>
<tests xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    <class name="JTestCaseTest">
        <method name="testDateType" test-case="first-testcase">
                <param name="a_JavaUtilDate" type="java.util.Date">01.08.2003</param>
        <method name="testParamGroups" test-case="second-testcase">
                <param name="key" type="java.lang.String">key</param>
Because of the simple structure and the ease of use JTestCase set the foundation for further research and development.

The major points JTestCase was missing then were

  • no direct extension from JUnit TestCase class. Just a set of helper classes to be used for data retrieval.
  • A missing mapping for arbitrary 'value object' like Java structures.
    We are using a lot of them in actual projects. A good part of these objects are write protected, that means only creatable with special constructor or through Java reflection.
  • No referencing between objects like used in complex structures as order objects or other business structures.
The lack of this features set the gound for the basic ideas and features of DDTUnit.
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