Today, the SolrCloud tests are based on the LuceneTestCase class hierarchy, which has a couple of issues around support for downstream projects:
- It's difficult to test SolrCloud support in a downstream project that may have its own test framework. For example, some projects have support for different storage backends (e.g. Solr/ElasticSearch/HBase) and want tests against each of the different backends. This is difficult to do cleanly, because the Solr tests require derivation from LuceneTestCase, while the other don't
- The LuceneTestCase class hierarchy is really designed for internal solr tests (e.g. it randomizes a lot of parameters to get test coverage, but a downstream project probably doesn't care about that). It's also quite complicated and dense, much more so than a downstream project would want.
Given these reasons, it would be nice to provide a simple "MiniSolrCloudCluster", similar to how HDFS provides a MiniHdfsCluster or HBase provides a MiniHBaseCluster.