Create float type family

docs/changelog/96625.yaml

@@ -0,0 +1,6 @@
+pr: 96625
+summary: Create float type family
+area: Mapping
+type: enhancement
+issues:
+ - 67723

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

@@ -243,6 +243,11 @@ public String typeName() {
             return CONTENT_TYPE;
         }
 
+        @Override
+        public String familyTypeName() {
+            return NumberFieldMapper.NumberType.FLOAT.typeName();
+        }
+
         @Override
         public boolean mayExistInIndex(SearchExecutionContext context) {
             return context.fieldExistsInIndex(name());

modules/mapper-extras/src/test/java/org/elasticsearch/index/mapper/extras/ScaledFloatFieldTypeTests.java

@@ -176,6 +176,12 @@ public void testValueForSearch() {
         assertEquals(10 / ft.getScalingFactor(), ft.valueForDisplay(10L));
     }
 
+    public void testFieldFamilyTypeIsReportedCorrectly() {
+        ScaledFloatFieldMapper.ScaledFloatFieldType ft = new ScaledFloatFieldMapper.ScaledFloatFieldType("scaled_float", 0.1);
+        var expectedFamilyType = NumberFieldMapper.NumberType.FLOAT.typeName();
+        assertEquals(expectedFamilyType, ft.familyTypeName());
+    }
+
     public void testFieldData() throws IOException {
         double scalingFactor = 0.1 + randomDouble() * 100;
         Directory dir = newDirectory();

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

@@ -326,6 +326,11 @@ public Float parse(XContentParser parser, boolean coerce) throws IOException {
                 return parsed;
             }
 
+            @Override
+            public String familyTypeName() {
+                return NumberFieldMapper.NumberType.FLOAT.typeName();
+            }
+
             @Override
             public Query termQuery(String field, Object value, boolean isIndexed) {
                 float v = parseToFloat(value);
@@ -1219,6 +1224,10 @@ public final String typeName() {
             return name;
         }
 
+        public String familyTypeName() {
+            return typeName();
+        }
+
         /** Get the associated numeric type */
         public final NumericType numericType() {
             return numericType;
@@ -1521,6 +1530,11 @@ public String typeName() {
             return type.name;
         }
 
+        @Override
+        public String familyTypeName() {
+            return this.type.familyTypeName();
+        }
+
         /**
          * This method reinterprets a double precision value based on the maximum precision of the stored number field.  Mostly this
          * corrects for unrepresentable values which have different approximations when cast from floats than when parsed as doubles.

server/src/test/java/org/elasticsearch/action/fieldcaps/FieldCapabilitiesFilterTests.java

@@ -19,6 +19,34 @@
 
 public class FieldCapabilitiesFilterTests extends MapperServiceTestCase {
 
+    /**
+     * Tests that the field family type is returned instead of the actual field type.
+     * `half_float` is chosen arbitrarily for this purpose.
+     */
+    public void testFieldFamilyTypeIsReturned() throws IOException {
+        MapperService mapperService = createMapperService("""
+            {
+              "_doc": {
+                "properties": {
+                  "field1": { "type": "half_float"}
+                }
+              }
+            }
+            """);
+        SearchExecutionContext sec = createSearchExecutionContext(mapperService);
+
+        Map<String, IndexFieldCapabilities> response = FieldCapabilitiesFetcher.retrieveFieldCaps(
+            sec,
+            new String[] { "*" },
+            new String[] {},
+            Strings.EMPTY_ARRAY,
+            f -> true
+        );
+
+        var expectedFamilyType = "float";
+        assertEquals(expectedFamilyType, response.get("field1").getType());
+    }
+
     public void testExcludeNestedFields() throws IOException {
         MapperService mapperService = createMapperService("""
             { "_doc" : {

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

@@ -57,6 +57,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 import java.util.function.Supplier;
 
 import static java.util.Collections.emptyMap;
@@ -744,6 +745,18 @@ public void write(XContentBuilder b) throws IOException {
         }
     }
 
+    public void testFieldFamilyTypeIsReportedCorrectly() {
+        for (NumberFieldMapper.NumberType type : NumberFieldMapper.NumberType.values()) {
+            NumberFieldMapper.NumberFieldType fieldType = new NumberFieldMapper.NumberFieldType("field", type);
+            var floatFamilyTypes = Set.of(NumberType.FLOAT.typeName(), NumberType.HALF_FLOAT.typeName());
+            if (floatFamilyTypes.contains(fieldType.typeName())) {
+                assertEquals(NumberType.FLOAT.typeName(), type.familyTypeName());
+            } else {
+                assertEquals(type.typeName(), type.familyTypeName());
+            }
+        }
+    }
+
     public void testDisplayValue() {
         for (NumberFieldMapper.NumberType type : NumberFieldMapper.NumberType.values()) {
             NumberFieldMapper.NumberFieldType fieldType = new NumberFieldMapper.NumberFieldType("field", type);