Testing our Provider

What you will learn in this section

In this section we will create a whitebox JUnit test for our simple.provider implementation. JUnit tests are very cheap; using them extensively saves tremendous amount of times in later phases of the development process. JUnit tests are always run before code is released and when they fail, they prohibit the release of the project.

These JUnit tests run outside the OSGi Framework.

Testing is one of those chores a developer has to do, not as much fun as some deep algorithmic code. However, it is likely one of the most effective ways to spend your time.

Make sure you are in the top directory:

$ cd ~/workspaces/osgi.enroute.examples.eval

JUnit

A provider should always have unit tests. Unit tests are white box tests. The test knows about the implementation details and it can even see aspects of the components that are not part of the public API.

Since the JUnit tests run outside OSGi it pays off to design the implementation in such a way that you have OSGi specific parts that then parameterize calls to plain old java objects (POJO). These POJOs can then be tested independently

In Maven, we have to write our test cases in src/test/java.

osgi.enroute.examples.eval $ cd simple.provider
simple.provider $ mkdir -p src/test/java/osgi/enroute/examples/eval/simple/provider
simple.provider $ vi src/test/java/osgi/enroute/examples/eval/simple/provider/EvalImplTest.java
// copy the following source

package osgi.enroute.examples.eval.simple.provider;

import junit.framework.TestCase;
import osgi.enroute.examples.eval.provider.EvalImpl;

public class EvalImplTest extends TestCase {
	public void testSimple() throws Exception {
		EvalImpl t = new EvalImpl();
		assertEquals(3.0, t.eval("1 + 2"));
	}
}

We can run this test from maven:

simple.provider $ mvn test
...
-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running com.acme.prime.eval.provider.EvalImplTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.014 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
...

What Did We Learn?

In this section we learned how to write a plain JUnit test that tests the implementation but does not require an OSGi runtime.