Writing unit tests for AEM (part 2): Maven Setup

In the previous post I showed you how easy it is to start using SlingContext. If you start to use this approach in your own project and just copy the code, your Maven build is likely to fail with messages like this:

[ERROR] testActivate_unconfiguredParams(de.joerghoh.cqdump.samples.unittest.ReplicationServletTest)  Time elapsed: 0.01 s  <<< ERROR!
org.apache.sling.testing.mock.osgi.NoScrMetadataException: No OSGi SCR metadata found for class de.joerghoh.cqdump.samples.unittest.ReplicationServlet
    at org.apache.sling.testing.mock.osgi.OsgiServiceUtil.injectServices(OsgiServiceUtil.java:381)

The problem here is not the use of the SlingMock library itself, but rather the fact that we use SlingMocks to test code which uses OSGI annotations. The fix itself is quite straight-forward: We need to create OSGI metadata also for the unittests and not only for the bundling (SlingMock is reading these metadata for the test execution).

That’s the reason why there’s the need to have a dedicated execution definition for the maven-bundle-plugin:

Also you need to instruct the maven-bundle-plugin to actually export the generated metadata to the filesystem using the “<exportScr> statements; this should be the default in my opinion, but you need to specify it explicitly. Also don’t forget to add the “_dsannotation” and “_metatypeannotations” statements to its instruction section:

And even then it will fail, if you don’t upgrade the maven-bundle-plugin to a version later than 4.0:

Ok, if you adapted your POMs in this way, your SlingMock based unittests for OSGI r6-based services should run fine. Now you can start exploring more features of SlingMocks.