protected void setSearchContext(String[] types) {
    final MapperService mapperService = queryParserService().mapperService;
    final IndexFieldDataService fieldData = queryParserService().fieldDataService;
    TestSearchContext testSearchContext =
        new TestSearchContext() {
          private InnerHitsContext context;

          @Override
          public void innerHits(InnerHitsContext innerHitsContext) {
            context = innerHitsContext;
          }

          @Override
          public InnerHitsContext innerHits() {
            return context;
          }

          @Override
          public MapperService mapperService() {
            return mapperService; // need to build / parse inner hits sort fields
          }

          @Override
          public IndexFieldDataService fieldData() {
            return fieldData; // need to build / parse inner hits sort fields
          }
        };
    testSearchContext.setTypes(types);
    SearchContext.setCurrent(testSearchContext);
  }
  /**
   * Assert that the {@code scoreType} operates as expected and parents are found in the expected
   * order.
   *
   * <p>This will use the test index's parent/child types to create parents with multiple children.
   * Each child will have a randomly generated scored stored in {@link #CHILD_SCORE_NAME}, which is
   * used to score based on the {@code scoreType} by using a {@link MockScorer} to determine the
   * expected scores.
   *
   * @param scoreType The score type to use within the query to score parents relative to their
   *     children.
   * @throws IOException if any unexpected error occurs
   */
  private void assertScoreType(ScoreType scoreType) throws IOException {
    SearchContext context = SearchContext.current();
    Directory directory = newDirectory();
    IndexWriter writer =
        new IndexWriter(directory, newIndexWriterConfig(new MockAnalyzer(random())));

    // calculates the expected score per parent
    MockScorer scorer = new MockScorer(scoreType);
    scorer.scores = new FloatArrayList(10);

    // number of parents to generate
    int parentDocs = scaledRandomIntBetween(2, 10);
    // unique child ID
    int childDocId = 0;

    // Parent ID to expected score
    Map<String, Float> parentScores = new TreeMap<>();

    // Add a few random parents to ensure that the children's score is appropriately taken into
    // account
    for (int parentDocId = 0; parentDocId < parentDocs; ++parentDocId) {
      String parent = Integer.toString(parentDocId);

      // Create the parent
      Document parentDocument = new Document();

      parentDocument.add(
          new StringField(UidFieldMapper.NAME, Uid.createUid("parent", parent), Field.Store.YES));
      parentDocument.add(new StringField(IdFieldMapper.NAME, parent, Field.Store.YES));
      parentDocument.add(new StringField(TypeFieldMapper.NAME, "parent", Field.Store.NO));

      // add the parent to the index
      writer.addDocument(parentDocument);

      int numChildDocs = scaledRandomIntBetween(1, 10);

      // forget any parent's previous scores
      scorer.scores.clear();

      // associate children with the parent
      for (int i = 0; i < numChildDocs; ++i) {
        int childScore = random().nextInt(128);

        Document childDocument = new Document();

        childDocument.add(
            new StringField(
                UidFieldMapper.NAME,
                Uid.createUid("child", Integer.toString(childDocId++)),
                Field.Store.NO));
        childDocument.add(new StringField(TypeFieldMapper.NAME, "child", Field.Store.NO));
        // parent association:
        childDocument.add(
            new StringField(
                ParentFieldMapper.NAME, Uid.createUid("parent", parent), Field.Store.NO));
        childDocument.add(new DoubleField(CHILD_SCORE_NAME, childScore, Field.Store.NO));

        // remember the score to be calculated
        scorer.scores.add(childScore);

        // add the associated child to the index
        writer.addDocument(childDocument);
      }

      // this score that should be returned for this parent
      parentScores.put(parent, scorer.score());
    }

    writer.commit();

    IndexReader reader = DirectoryReader.open(writer, true);
    IndexSearcher searcher = new IndexSearcher(reader);

    // setup to read the parent/child map
    Engine.Searcher engineSearcher =
        new Engine.Searcher(ChildrenQueryTests.class.getSimpleName(), searcher);
    ((TestSearchContext) context).setSearcher(new ContextIndexSearcher(context, engineSearcher));

    // child query that returns the score as the value of "childScore" for each child document, with
    // the parent's score determined by the score type
    QueryBuilder childQueryBuilder =
        functionScoreQuery(typeFilter("child"))
            .add(new FieldValueFactorFunctionBuilder(CHILD_SCORE_NAME));
    QueryBuilder queryBuilder =
        hasChildQuery("child", childQueryBuilder)
            .scoreType(scoreType.name().toLowerCase(Locale.ENGLISH))
            .setShortCircuitCutoff(parentDocs);

    // Perform the search for the documents using the selected score type
    TopDocs docs = searcher.search(parseQuery(queryBuilder), parentDocs);
    assertThat("Expected all parents", docs.totalHits, is(parentDocs));

    // score should be descending (just a sanity check)
    float topScore = docs.scoreDocs[0].score;

    // ensure each score is returned as expected
    for (int i = 0; i < parentDocs; ++i) {
      ScoreDoc scoreDoc = docs.scoreDocs[i];
      // get the ID from the document to get its expected score; remove it so we cannot double-count
      // it
      float score = parentScores.remove(reader.document(scoreDoc.doc).get(IdFieldMapper.NAME));

      // expect exact match
      assertThat("Unexpected score", scoreDoc.score, is(score));
      assertThat("Not descending", score, lessThanOrEqualTo(topScore));

      // it had better keep descending
      topScore = score;
    }

    reader.close();
    writer.close();
    directory.close();
  }