refactor: create enum class for label type

pom.xml

@@ -6,7 +6,7 @@
 	<artifactId>lunatic-model</artifactId>
 	<packaging>jar</packaging>
 
-	<version>3.2.5</version>
+	<version>3.2.6-SNAPSHOT</version>
 	<name>Lunatic Model</name>
 	<description>Classes and converters for the Lunatic model</description>
 	<url>https://inseefr.github.io/Lunatic-Model/</url>

src/main/java/fr/insee/lunatic/model/flat/LabelType.java

@@ -1,5 +1,6 @@
 package fr.insee.lunatic.model.flat;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import lombok.Getter;
 import lombok.Setter;
@@ -8,10 +9,58 @@
         "value",
         "type"
 })
-@Getter
-@Setter
 public class LabelType {
 
+    @Getter @Setter
     protected String value;
+
     protected String type;
+    @JsonIgnore
+    private LabelTypeEnum typeEnum;
+
+    /**
+     * Get label type.
+     * @return String value of label type.
+     * @deprecated The string property is being replaced with an enum. Use the <code>getTypeEnum</code> method.
+     */
+    @Deprecated(since = "3.2.6")
+    public String getType() {
+        if (typeEnum != null)
+            return typeEnum.toString();
+        return type;
+    }
+
+    /**
+     * Set string label type.
+     * @param type String value of label type, can be either "VTL_MD" or "VTL".
+     * @deprecated The string property is being replaced with an enum.
+     */
+    @Deprecated(since = "3.2.6")
+    public void setType(String type) {
+        if (! ("VTL_MD".equals(type) || "VTL".equals(type)))
+            throw new IllegalArgumentException("Label type can be either \"VTL_MD\" or \"VTL\".");
+        this.type = type;
+        this.typeEnum = null;
+    }
+
+    /**
+     * Temporary getter for the type property being changed to an enum. In a future version, the <code>getType</code>
+     * will return the proper label type.
+     * @return Label type.
+     */
+    public LabelTypeEnum getTypeEnum() {
+        if (type != null)
+            return LabelTypeEnum.valueOf(type);
+        return typeEnum;
+    }
+
+    /**
+     * Set label type.
+     * @param labelTypeEnum Label type.
+     */
+    public void setType(LabelTypeEnum labelTypeEnum) {
+        this.type = null;
+        this.typeEnum = labelTypeEnum;
+    }
+
 }

src/main/java/fr/insee/lunatic/model/flat/LabelTypeEnum.java

@@ -0,0 +1,10 @@
+package fr.insee.lunatic.model.flat;
+
+public enum LabelTypeEnum {
+
+    /** Label that is a VTL expression and contains Markdown formatting. */
+    VTL_MD,
+    /** Label that is a VTL expression. */
+    VTL
+
+}

src/test/java/fr/insee/lunatic/conversion/LabelSerializationTest.java

@@ -0,0 +1,69 @@
+package fr.insee.lunatic.conversion;
+
+import fr.insee.lunatic.exception.SerializationException;
+import fr.insee.lunatic.model.flat.LabelType;
+import fr.insee.lunatic.model.flat.LabelTypeEnum;
+import fr.insee.lunatic.model.flat.Questionnaire;
+import org.json.JSONException;
+import org.junit.jupiter.api.Test;
+import org.skyscreamer.jsonassert.JSONAssert;
+import org.skyscreamer.jsonassert.JSONCompareMode;
+
+import java.io.ByteArrayInputStream;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class LabelSerializationTest {
+
+    @Test
+    void serializeFromQuestionnaire_usingEnumType() throws SerializationException, JSONException {
+        //
+        Questionnaire questionnaire = new Questionnaire();
+        LabelType label = new LabelType();
+        label.setValue("Foo label");
+        label.setType(LabelTypeEnum.VTL_MD);
+        questionnaire.setLabel(label);
+        //
+        JsonSerializer jsonSerializer = new JsonSerializer();
+        String result = jsonSerializer.serialize(questionnaire);
+        //
+        String expected = """
+                {"label": {"value": "Foo label", "type": "VTL_MD"}}
+                """;
+        JSONAssert.assertEquals(expected, result, JSONCompareMode.STRICT);
+    }
+
+    @Test
+    void serializeFromQuestionnaire_usingStringType() throws SerializationException, JSONException {
+        //
+        Questionnaire questionnaire = new Questionnaire();
+        LabelType label = new LabelType();
+        label.setValue("Foo label");
+        label.setType("VTL_MD");
+        questionnaire.setLabel(label);
+        //
+        JsonSerializer jsonSerializer = new JsonSerializer();
+        String result = jsonSerializer.serialize(questionnaire);
+        //
+        String expected = """
+                {"label": {"value": "Foo label", "type": "VTL_MD"}}
+                """;
+        JSONAssert.assertEquals(expected, result, JSONCompareMode.STRICT);
+    }
+
+    @Test
+    void deserializeFromQuestionnaire() throws SerializationException {
+        //
+        String jsonInput = """
+                {"label": {"value": "Foo label", "type": "VTL_MD"}}
+                """;
+        //
+        JsonDeserializer jsonDeserializer = new JsonDeserializer();
+        Questionnaire questionnaire = jsonDeserializer.deserialize(new ByteArrayInputStream(jsonInput.getBytes()));
+        //
+        LabelType label = questionnaire.getLabel();
+        assertEquals(LabelTypeEnum.VTL_MD, label.getTypeEnum());
+        assertEquals("VTL_MD", label.getType());
+    }
+
+}