public void testReallyNoNormsForDrillDown() throws Exception {
  Directory dir = newDirectory();
  Directory taxoDir = newDirectory();
  IndexWriterConfig iwc = newIndexWriterConfig(new MockAnalyzer(random()));
  iwc.setSimilarity(new PerFieldSimilarityWrapper() {
      final Similarity sim = new ClassicSimilarity();

      @Override
      public Similarity get(String name) {
        assertEquals("field", name);
        return sim;
      }
    });
  TaxonomyWriter taxoWriter = new DirectoryTaxonomyWriter(taxoDir, IndexWriterConfig.OpenMode.CREATE);
  RandomIndexWriter writer = new RandomIndexWriter(random(), dir, iwc);
  FacetsConfig config = new FacetsConfig();

  Document doc = new Document();
  doc.add(newTextField("field", "text", Field.Store.NO));
  doc.add(new FacetField("a", "path"));
  writer.addDocument(config.build(taxoWriter, doc));
  writer.close();
  IOUtils.close(taxoWriter, dir, taxoDir);
}
 

@Override
public void setUp() throws Exception {
  super.setUp();
  directory = newDirectory();
  PerFieldSimilarityWrapper sim = new ExampleSimilarityProvider();
  IndexWriterConfig iwc = newIndexWriterConfig(new MockAnalyzer(random())).setSimilarity(sim);
  RandomIndexWriter iw = new RandomIndexWriter(random(), directory, iwc);
  Document doc = new Document();
  Field field = newTextField("foo", "", Field.Store.NO);
  doc.add(field);
  Field field2 = newTextField("bar", "", Field.Store.NO);
  doc.add(field2);

  field.setStringValue("quick brown fox");
  field2.setStringValue("quick brown fox");
  iw.addDocument(doc);
  field.setStringValue("jumps over lazy brown dog");
  field2.setStringValue("jumps over lazy brown dog");
  iw.addDocument(doc);
  reader = iw.getReader();
  iw.close();
  searcher = newSearcher(reader);
  searcher.setSimilarity(sim);
}
 

/**
 * whitebox checks the Similarity for the specified field according to {@link SolrCore#getLatestSchema}
 * 
 * Executes each of the specified Similarity-accepting validators.
 */
@SafeVarargs
@SuppressWarnings({"unchecked", "varargs"})
private static <T extends Similarity> void assertFieldSimilarity(String fieldname, Class<T> expected, Consumer<T>... validators) {
  CoreContainer cc = jetty.getCoreContainer();
  try (SolrCore core = cc.getCore("collection1")) {
    SimilarityFactory simfac = core.getLatestSchema().getSimilarityFactory();
    assertNotNull(simfac);
    assertTrue("test only works with SchemaSimilarityFactory",
               simfac instanceof SchemaSimilarityFactory);
    
    Similarity mainSim = core.getLatestSchema().getSimilarity();
    assertNotNull(mainSim);
    
    // sanity check simfac vs sim in use - also verify infom called on simfac, otherwise exception
    assertEquals(mainSim, simfac.getSimilarity());
    
    assertTrue("test only works with PerFieldSimilarityWrapper, SchemaSimilarityFactory redefined?",
               mainSim instanceof PerFieldSimilarityWrapper);
    Similarity fieldSim = ((PerFieldSimilarityWrapper)mainSim).get(fieldname);
    assertEquals("wrong sim for field=" + fieldname, expected, fieldSim.getClass());
    Arrays.asList(validators).forEach(v -> v.accept((T)fieldSim));
  }
}
 

static TFIDFSimilarity asTFIDF(Similarity sim, String field) {
  while (sim instanceof PerFieldSimilarityWrapper) {
    sim = ((PerFieldSimilarityWrapper)sim).get(field);
  }
  if (sim instanceof TFIDFSimilarity) {
    return (TFIDFSimilarity)sim;
  } else {
    return null;
  }
}
 

/** returns the similarity in use for the field */
protected Similarity getSimilarity(String field) {
  Similarity sim = null;
  try {
    sim = h.getCore().withSearcher(IndexSearcher::getSimilarity);
  } catch (IOException e) {
    throw new RuntimeException(e);
  }
  while (sim instanceof PerFieldSimilarityWrapper) {
    sim = ((PerFieldSimilarityWrapper)sim).get(field);
  }
  return sim;
}
 

private PerFieldSimilarityWrapper getSimilarity(final QueryWithFilters queryWithFilters) {
	return new PerFieldSimilarityWrapper() {
		@Override
		public Similarity get(String name) {

			AnalyzerSettings analyzerSettings = indexConfig.getAnalyzerSettingsForIndexField(name);
			AnalyzerSettings.Similarity similarity = AnalyzerSettings.Similarity.BM25;
			if (analyzerSettings != null) {
				similarity = analyzerSettings.getSimilarity();
			}

			AnalyzerSettings.Similarity fieldSimilarityOverride = queryWithFilters.getFieldSimilarityOverride(name);
			if (fieldSimilarityOverride != null) {
				similarity = fieldSimilarityOverride;
			}

			if (AnalyzerSettings.Similarity.TFIDF.equals(similarity)) {
				return new ClassicSimilarity();
			}
			else if (AnalyzerSettings.Similarity.BM25.equals(similarity)) {
				return new BM25Similarity();
			}
			else if (AnalyzerSettings.Similarity.CONSTANT.equals(similarity)) {
				return new ConstantSimilarity();
			}
			else if (AnalyzerSettings.Similarity.TF.equals(similarity)) {
				return new TFSimilarity();
			}
			else {
				throw new RuntimeException("Unknown similarity type <" + similarity + ">");
			}
		}
	};
}