The test class `KeywordFieldMapperTests` contains a switch statement with a branch that will never execute. The test uses a `between(x, y)` switch expression, but the `4` case is outside the randomised range. We need to fix this before #88739 can be merged. By "fix", I mean either remove the spurious case, or if we actually want it then extend the randomized range.
server/src/test/java/org/elasticsearch/index/mapper/KeywordFieldMapperTests.java
public void testEnableNorms() throws IOException {
        DocumentMapper mapper = createDocumentMapper(
            fieldMapping(b -> b.field("type", "keyword").field("doc_values", false).field("norms", true))
        );
        ParsedDocument doc = mapper.parse(source(b -> b.field("field", "1234")));
        IndexableField[] fields = doc.rootDoc().getFields("field");
        assertEquals(1, fields.length);
        assertFalse(fields[0].fieldType().omitNorms());
        IndexableField[] fieldNamesFields = doc.rootDoc().getFields(FieldNamesFieldMapper.NAME);
        assertEquals(0, fieldNamesFields.length);
    }
    public void testDimension() throws IOException {
        
        MapperService mapperService = createMapperService(fieldMapping(b -> minimalMapping(b)));
        KeywordFieldMapper.KeywordFieldType ft = (KeywordFieldMapper.KeywordFieldType) mapperService.fieldType("field");
        assertFalse(ft.isDimension());
        assertDimension(true, KeywordFieldMapper.KeywordFieldType::isDimension);
        assertDimension(false, KeywordFieldMapper.KeywordFieldType::isDimension);
    }
    public void testDimensionAndIgnoreAbove() {
        Exception e = expectThrows(MapperParsingException.class, () -> createDocumentMapper(fieldMapping(b -> {
            minimalMapping(b);
            b.field("time_series_dimension", true).field("ignore_above", 2048);
        })));
        assertThat(
            e.getCause().getMessage(),
            containsString("Field [ignore_above] cannot be set in conjunction with field [time_series_dimension]")
        );
    }
    public void testDimensionAndNormalizer() {