fix: add unit test

core/src/test/java/io/kestra/core/serializers/YamlParserTest.java

@@ -3,6 +3,7 @@ package io.kestra.core.serializers;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import io.kestra.core.models.flows.Flow;
+import io.kestra.core.models.flows.FlowWithSource;
 import io.kestra.core.models.flows.Input;
 import io.kestra.core.models.flows.Type;
 import io.kestra.core.models.flows.input.StringInput;
@@ -32,6 +33,7 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 @KestraTest
 class YamlParserTest {
     private static final ObjectMapper MAPPER = JacksonMapper.ofJson();
+    private static final ObjectMapper OBJECT_MAPPER = JacksonMapper.ofYaml().copy();
 
     @Inject
     private ModelValidator modelValidator;
@@ -235,6 +237,29 @@ class YamlParserTest {
         assertThat(new ArrayList<>(exception.getConstraintViolations()).getFirst().getMessage()).contains("Duplicate field 'variables.tf'");
     }
 
+    @Test
+    void vaildLabelsParser() throws IOException {
+        Flow flow = parse("flows/valids/labels-deserialization.yaml");
+        // like change execution state api,Serialize flow to YAML/JSON string
+        String s = OBJECT_MAPPER.writeValueAsString(flow);
+        assertThat(s).isEqualTo("id: full\n" +
+            "namespace: io.kestra.tests\n" +
+            "disabled: false\n" +
+            "deleted: false\n" +
+            "labels:\n" +
+            "- key: key1\n" +
+            "  value: 123\n" +
+            "tasks:\n" +
+            "- id: t1\n" +
+            "  type: io.kestra.plugin.core.log.Log\n" +
+            "  message: \"{{ task.id }}\"\n");
+        Map<String, Object> mapFlow = OBJECT_MAPPER.readValue(s, JacksonMapper.MAP_TYPE_REFERENCE);
+        // Parse into FlowWithSource (simulates state update scenario)
+        FlowWithSource parse = YamlParser.parse(mapFlow, FlowWithSource.class, false);
+
+        assertThat(parse.getLabels().size()).isEqualTo(1);;
+    }
+
     private Flow parse(String path) {
         URL resource = TestsUtils.class.getClassLoader().getResource(path);
         assert resource != null;

core/src/test/resources/flows/valids/labels-deserialization.yaml

@@ -0,0 +1,17 @@
+id: full
+namespace: io.kestra.tests
+labels:
+  key1: 123
+
+#triggers:
+#- type: schedule
+#  expression: 42 4 1 * *
+#  backfill:
+#    start: 2018-01-01
+#    depend-on-past: false
+#
+
+tasks:
+  - id: t1
+    type: io.kestra.plugin.core.log.Log
+    message: "{{ task.id }}"