Add specific test for serializing all mapping parameter values (#61844)…

… (#61877)

This commit adds a test to MapperTestCase that explicitly checks that a mapper can
serialize all its default values, and that this serialization can then be re-parsed. Note that
the test is disabled for non-parametrized mappers as their serialization may in some cases
output parameters that are not accepted. Gradually moving all mappers to parametrized
form will address this.

The commit also contains a fix to keyword mappers, which were not correctly serializing
the similarity parameter; this partially addresses #61563. It also enables `null` as a
value for `null_value` on `scaled_float`, as a follow-up to #61798

modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/ScaledFloatFieldMapper.java

@@ -93,7 +93,7 @@ public static class Builder extends ParametrizedFieldMapper.Builder {
  }
  });
  private final Parameter<Double> nullValue = new Parameter<>("null_value", false, () -> null,
- (n, c, o) -> XContentMapValues.nodeDoubleValue(o), m -> toType(m).nullValue);
+ (n, c, o) -> o == null ? null : XContentMapValues.nodeDoubleValue(o), m -> toType(m).nullValue).acceptsNull();
 
  private final Parameter<Map<String, String>> meta = Parameter.metaParam();
 

server/src/main/java/org/elasticsearch/index/mapper/KeywordFieldMapper.java

@@ -100,7 +100,9 @@ public static class Builder extends ParametrizedFieldMapper.Builder {
  private final Parameter<Boolean> hasNorms
  = Parameter.boolParam("norms", false, m -> toType(m).fieldType.omitNorms() == false, false);
  private final Parameter<SimilarityProvider> similarity = new Parameter<>("similarity", false, () -> null,
- (n, c, o) -> TypeParsers.resolveSimilarity(c, n, o.toString()), m -> toType(m).similarity);
+ (n, c, o) -> TypeParsers.resolveSimilarity(c, n, o), m -> toType(m).similarity)
+ .setSerializer((b, f, v) -> b.field(f, v == null ? null : v.name()), v -> v == null ? null : v.name())
+ .acceptsNull();
 
  private final Parameter<String> normalizer
  = Parameter.stringParam("normalizer", false, m -> toType(m).normalizerName, "default");

server/src/main/java/org/elasticsearch/index/mapper/TypeParsers.java

@@ -390,8 +390,11 @@ public static List<String> parseCopyFields(Object propNode) {
  return copyFields;
  }
 
- public static SimilarityProvider resolveSimilarity(Mapper.TypeParser.ParserContext parserContext, String name, String value) {
- SimilarityProvider similarityProvider = parserContext.getSimilarity(value);
+ public static SimilarityProvider resolveSimilarity(Mapper.TypeParser.ParserContext parserContext, String name, Object value) {
+ if (value == null) {
+ return null; // use default
+ }
+ SimilarityProvider similarityProvider = parserContext.getSimilarity(value.toString());
  if (similarityProvider == null) {
  throw new MapperParsingException("Unknown Similarity type [" + value + "] for field [" + name + "]");
  }

server/src/test/java/org/elasticsearch/index/mapper/KeywordFieldMapperTests.java

@@ -250,6 +250,18 @@ public void testEnableNorms() throws IOException {
  assertEquals(0, fieldNamesFields.length);
  }
 
+ public void testConfigureSimilarity() throws IOException {
+ MapperService mapperService = createMapperService(
+ fieldMapping(b -> b.field("type", "keyword").field("similarity", "boolean"))
+ );
+ MappedFieldType ft = mapperService.documentMapper().fieldTypes().get("field");
+ assertEquals("boolean", ft.getTextSearchInfo().getSimilarity().name());
+
+ IllegalArgumentException e = expectThrows(IllegalArgumentException.class,
+ () -> merge(mapperService, fieldMapping(b -> b.field("type", "keyword").field("similarity", "BM25"))));
+ assertThat(e.getMessage(), containsString("Cannot update parameter [similarity] from [boolean] to [BM25]"));
+ }
+
  public void testNormalizer() throws IOException {
  DocumentMapper mapper = createDocumentMapper(fieldMapping(b -> b.field("type", "keyword").field("normalizer", "lowercase")));
  ParsedDocument doc = mapper.parse(source(b -> b.field("field", "AbC")));

test/framework/src/main/java/org/elasticsearch/index/mapper/FieldMapperTestCase2.java

@@ -230,4 +230,9 @@ private XContentBuilder mappingsToJson(ToXContent builder, boolean includeDefaul
  : ToXContent.EMPTY_PARAMS;
  return mapping(b -> builder.toXContent(b, params));
  }
+
+ @Override
+ public void testMinimalToMaximal() {
+ assumeFalse("`include_defaults` includes unsupported properties in non-parametrized mappers", false);
+ }
 }

test/framework/src/main/java/org/elasticsearch/index/mapper/MapperServiceTestCase.java

@@ -30,6 +30,7 @@
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentType;
@@ -49,6 +50,7 @@
 
 import java.io.IOException;
 import java.util.Collection;
+import java.util.Collections;
 
 import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
@@ -63,6 +65,9 @@ public abstract class MapperServiceTestCase extends ESTestCase {
 
  protected static final Settings SETTINGS = Settings.builder().put("index.version.created", Version.CURRENT).build();
 
+ protected static final ToXContent.Params INCLUDE_DEFAULTS
+ = new ToXContent.MapParams(Collections.singletonMap("include_defaults", "true"));
+
  protected Collection<? extends Plugin> getPlugins() {
  return emptyList();
  }

test/framework/src/main/java/org/elasticsearch/index/mapper/MapperTestCase.java

@@ -63,6 +63,18 @@ public final void testMinimalSerializesToItself() throws IOException {
  assertParseMinimalWarnings();
  }
 
+ // TODO make this final once we remove FieldMapperTestCase2
+ public void testMinimalToMaximal() throws IOException {
+ XContentBuilder orig = JsonXContent.contentBuilder().startObject();
+ createMapperService(fieldMapping(this::minimalMapping)).documentMapper().mapping().toXContent(orig, INCLUDE_DEFAULTS);
+ orig.endObject();
+ XContentBuilder parsedFromOrig = JsonXContent.contentBuilder().startObject();
+ createMapperService(orig).documentMapper().mapping().toXContent(parsedFromOrig, INCLUDE_DEFAULTS);
+ parsedFromOrig.endObject();
+ assertEquals(Strings.toString(orig), Strings.toString(parsedFromOrig));
+ assertParseMinimalWarnings();
+ }
+
  protected void assertParseMinimalWarnings() {
  // Most mappers don't emit any warnings
  }