Upgrading a library bundle to a newer version does NOT break compatibility with Sling's downstream systems. It is not like upgrading from Java 7 to 8 or from Declarative Services 1.2 to 1.3.
If you can deploy a newer version of a components/services bundle which runs as singleton (e.g. HC Core) to an older system (e.g. AEM 6.1) you can easily deploy a library bundle (whether you upgrade the older one or run both in parallel). If you want to keep (for what ever reason) the older one and deploying both in parallel does not work because of a limitation in OSGi Installer, OSGi Installer should be improved. In my opinion we should always test our artifacts with current dependencies (dependencies in Launchpad, a well known set). Older artifacts were already tested with older dependencies. That is currently the case for org.apache.sling.launchpad.integration-tests mostly. For unit tests and integration tests closer to the artifacts the setting is different, e.g. use of Commons Lang in version 2.0, 2.2, 2.4, 2.5, 2.6, 3.0, 3.0.1, 3.3.2 (similar for Commons IO, SLING-5685). So what's the point in testing with that outdated dependencies? I don't think there is support in Maven 3 for unit tests using a different version than for compile. Not sure if other build tools can handle different versions of dependencies for compile and test. So my preferred answers to eliminate outdated dependencies in tests: 1. use minimal version for compile and current version for test (how?) 2. use current version for compile and test 3. use current version for compile and test and carefully expand import range Not (never) upgrading dependencies (whether our own or 3rd party) may lead to nasty or unnecessary code, see Konrad's commit: http://svn.apache.org/viewvc/sling/trunk/bundles/extensions/validation/core/src/main/java/org/apache/sling/validation/impl/ValidationServiceImpl.java?r1=1740178&r2=1745478&pathrev=1745478&diff_format=h Why not upgrading Sling API to 2.7.0 (released two years ago) and use resource.getValueMap() instead? When do we drop support for older systems? Regards, O.
