Over a million developers have joined DZone.
Platinum Partner

Unit Tests - "Written Once and Forgotten Forever"

· Java Zone

The Java Zone is brought to you in partnership with AppDynamics. Discover how AppDynamics steps in to upgrade your performance game and prevent your enterprise from these top 10 Java performance problems.

I have come across many unit test cases that are written once and forgotten for ever, with all the dataset/environmental dependencies in it. What is the importance of dataset/environment? Let's take an example, observe the test case below.

public void testEmpFinder () {

//Weird Test case for Fun!!!

String result = "JOHN";

//Passing employee id returns employee object.

//verify the name matches.

Employee emp = EmpFinder.find(1);

assertEquals(emp.getName,result);

}

What's wrong? The developer had made an assumption, that on querying with employeeid='1' will return employee with the name "JOHN". The data could be coming from a database table "EMPLOYEE". But It’s very evident this test case would fail if run on an environment where the employeeid='1' data doesn't exists. This makes the test cases obsolete the moment they are written.

Approach

1. Save Insert/Delete datascript, that could be run on test setup () and delete test data on completion of test.

2. You could use something like DBUnit (http://www.dbunit.org/) which exports and imports the database data into an XML dataset. - Not sure of DBUnit support for modern day ORM's (Hibernate).

Conclusion:

Unit tests should match & sustain life time of source, after all its a guarantee card to your source code. We just looked at database dependency for example, how about dependencies such as JMS, Content Repository, LDAP etc. Writing a test case with all its data & environmental dependencies Mocked & externalized is an Art.

The Java Zone is brought to you in partnership with AppDynamics. AppDynamics helps you gain the fundamentals behind application performance, and implement best practices so you can proactively analyze and act on performance problems as they arise, and more specifically with your Java applications. Start a Free Trial.

Topics:

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}