Allow non-boolean return type for "is-getters" with MapperFeature.ALLOW_IS_GETTERS_FOR_NON_BOOLEAN (#3609)

Author: Richie94

src/main/java/com/fasterxml/jackson/databind/MapperFeature.java

@@ -486,6 +486,15 @@ public enum MapperFeature implements ConfigFeature
      */
     ALLOW_EXPLICIT_PROPERTY_RENAMING(false),
 
+    /**
+     * Feature that when enabled will allow getters with is-Prefix also for non-boolean return types.
+     * <p>
+     * Feature is disabled by default.
+     *
+     * @since 2.14
+     */
+    ALLOW_IS_GETTERS_FOR_NON_BOOLEAN(false),
+
     /*
     /******************************************************
     /* Coercion features

src/main/java/com/fasterxml/jackson/databind/introspect/DefaultAccessorNamingStrategy.java

@@ -41,6 +41,7 @@ public interface BaseNameValidator {
     protected final BaseNameValidator _baseNameValidator;
 
     protected final boolean _stdBeanNaming;
+    protected final boolean _isGettersNonBoolean;
 
     protected final String _getterPrefix;
     protected final String _isGetterPrefix;
@@ -59,6 +60,7 @@ protected DefaultAccessorNamingStrategy(MapperConfig<?> config, AnnotatedClass f
         _forClass = forClass;
 
         _stdBeanNaming = config.isEnabled(MapperFeature.USE_STD_BEAN_NAMING);
+        _isGettersNonBoolean = config.isEnabled(MapperFeature.ALLOW_IS_GETTERS_FOR_NON_BOOLEAN);
         _mutatorPrefix = mutatorPrefix;
         _getterPrefix = getterPrefix;
         _isGetterPrefix = isGetterPrefix;
@@ -70,7 +72,7 @@ public String findNameForIsGetter(AnnotatedMethod am, String name)
     {
         if (_isGetterPrefix != null) {
             final Class<?> rt = am.getRawType();
-            if (rt == Boolean.class || rt == Boolean.TYPE) {
+            if (_isGettersNonBoolean || rt == Boolean.class || rt == Boolean.TYPE) {
                 if (name.startsWith(_isGetterPrefix)) {
                     return _stdBeanNaming
                             ? stdManglePropertyName(name, 2)

src/test/java/com/fasterxml/jackson/databind/introspect/IsGetterBoolean3609Test.java

@@ -0,0 +1,57 @@
+package com.fasterxml.jackson.databind.introspect;
+
+import com.fasterxml.jackson.databind.BaseMapTest;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
+
+import java.util.Collections;
+import java.util.Map;
+
+import static com.fasterxml.jackson.databind.MapperFeature.ALLOW_IS_GETTERS_FOR_NON_BOOLEAN;
+
+public class IsGetterBoolean3609Test extends BaseMapTest {
+
+    static class POJO3609 {
+        int isEnabled;
+
+        protected POJO3609() { }
+        public POJO3609(int b) {
+            isEnabled = b;
+        }
+
+        public int isEnabled() { return isEnabled; }
+        public void setEnabled(int b) { isEnabled = b; }
+    }
+
+    public void testAllowIntIsGetter() throws Exception
+    {
+        ObjectMapper MAPPER = jsonMapperBuilder()
+                .enable(ALLOW_IS_GETTERS_FOR_NON_BOOLEAN)
+                .build();
+
+        POJO3609 input = new POJO3609(12);
+        final String json = MAPPER.writeValueAsString(input);
+
+        Map<?, ?> props = MAPPER.readValue(json, Map.class);
+        assertEquals(Collections.singletonMap("enabled", 12),
+                props);
+
+        POJO3609 output = MAPPER.readValue(json, POJO3609.class);
+        assertEquals(input.isEnabled, output.isEnabled);
+    }
+
+    public void testDisallowIntIsGetter() throws Exception
+    {
+        ObjectMapper MAPPER = jsonMapperBuilder()
+                .disable(ALLOW_IS_GETTERS_FOR_NON_BOOLEAN)
+                .disable(SerializationFeature.FAIL_ON_EMPTY_BEANS)
+                .build();
+
+        POJO3609 input = new POJO3609(12);
+        final String json = MAPPER.writeValueAsString(input);
+
+        assertEquals("{}", json);
+
+    }
+}