Fix #3110

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -31,6 +31,9 @@ Project: jackson-databind
    `JsonToken.VALUE_EMBEDDED_OBJECT`
 #3099: Optimize "AnnotatedConstructor.call()" case by passing explicit null
 #3101: Add AnnotationIntrospector.XmlExtensions interface for decoupling javax dependencies
+#3110: Custom SimpleModule not included in list returned by ObjectMapper.getRegisteredModuleIds()
+  after registration
+ (reported by dkindler@github)
 #3117: Use more limiting default visibility settings for JDK types (java.*, javax.*)
 #3122: Deep merge for `JsonNode` using `ObjectReader.readTree()`
  (reported by Eric S)

src/main/java/com/fasterxml/jackson/databind/module/SimpleModule.java

@@ -45,6 +45,16 @@ public class SimpleModule
     protected final String _name;
     protected final Version _version;
 
+    /**
+     * Flag that indicates whether module was given an explicit name
+     * or not. Distinction is used to determine whether method
+     * {@link #getTypeId()} should return name (yes, if explicit) or
+     * {@code null} (if no explicit name was passed).
+     *
+     * @since 2.13
+     */
+    protected final boolean _hasExplicitName;
+
     protected SimpleSerializers _serializers = null;
     protected SimpleDeserializers _deserializers = null;
 
@@ -109,8 +119,10 @@ public SimpleModule() {
                 "SimpleModule-"+System.identityHashCode(this)
                 : getClass().getName();
         _version = Version.unknownVersion();
+        // 07-Jun-2021, tatu: [databind#3110] Not passed explicitly so...
+        _hasExplicitName = false;
     }
-    
+
     /**
      * Convenience constructor that will default version to
      * {@link Version#unknownVersion()}.
@@ -121,13 +133,12 @@ public SimpleModule(String name) {
 
     /**
      * Convenience constructor that will use specified Version,
-     * including name from {@link Version#getArtifactId()}
+     * including name from {@link Version#getArtifactId()}.
      */
     public SimpleModule(Version version) {
-        _name = version.getArtifactId();
-        _version = version;
+        this(version.getArtifactId(), version);
     }
-    
+
     /**
      * Constructor to use for actual reusable modules.
      * ObjectMapper may use name as identifier to notice attempts
@@ -140,6 +151,8 @@ public SimpleModule(Version version) {
     public SimpleModule(String name, Version version) {
         _name = name;
         _version = version;
+        // 07-Jun-2021, tatu: [databind#3110] Is passed explicitly (may be `null`)
+        _hasExplicitName = true;
     }
 
     /**
@@ -166,6 +179,8 @@ public SimpleModule(String name, Version version,
             List<JsonSerializer<?>> serializers)
     {
         _name = name;
+        // 07-Jun-2021, tatu: [databind#3110] Is passed explicitly (may be `null`)
+        _hasExplicitName = true;
         _version = version;
         if (deserializers != null) {
             _deserializers = new SimpleDeserializers(deserializers);
@@ -181,13 +196,18 @@ public SimpleModule(String name, Version version,
      * but class name (default impl) for sub-classes.
      */
     @Override
-    public Object getTypeId() {
-        if (getClass() == SimpleModule.class) {
-            return null;
+    public Object getTypeId()
+    {
+        // 07-Jun-2021, tatu: [databind#3110] Only return Type Id if name
+        //    was explicitly given
+        if (_hasExplicitName) {
+            return _name;
         }
-        return super.getTypeId();
+        // ...otherwise give no type id, even for sub-classes (sub-classes are
+        // welcome to override this method of course)
+        return null;
     }
-    
+
     /*
     /**********************************************************
     /* Simple setters to allow overriding

src/test/java/com/fasterxml/jackson/databind/module/SimpleModuleTest.java

@@ -8,7 +8,7 @@
 import com.fasterxml.jackson.core.*;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.databind.*;
-
+import com.fasterxml.jackson.databind.json.JsonMapper;
 import com.fasterxml.jackson.databind.ser.std.StdScalarSerializer;
 import com.fasterxml.jackson.databind.ser.std.StdSerializer;
 
@@ -285,7 +285,12 @@ public void testSimpleEnumDeserializer() throws Exception
     public void testMultipleModules() throws Exception
     {
         MySimpleModule mod1 = new MySimpleModule("test1", Version.unknownVersion());
+        assertEquals("test1", mod1.getModuleName());
+        // 07-Jun-2021, tatu: as per [databind#3110]:
+        assertEquals("test1", mod1.getTypeId());
         SimpleModule mod2 = new SimpleModule("test2", Version.unknownVersion());
+        assertEquals("test2", mod2.getModuleName());
+        assertEquals("test2", mod2.getTypeId());
         mod1.addSerializer(SimpleEnum.class, new SimpleEnumSerializer());
         mod1.addDeserializer(CustomBean.class, new CustomBeanDeserializer());
 
@@ -315,10 +320,10 @@ public void testGetRegisteredModules()
         MySimpleModule mod1 = new MySimpleModule("test1", Version.unknownVersion());
         AnotherSimpleModule mod2 = new AnotherSimpleModule("test2", Version.unknownVersion());
 
-        ObjectMapper mapper = new ObjectMapper();
-
-        mapper.registerModule(mod1);
-        mapper.registerModule(mod2);
+        ObjectMapper mapper = JsonMapper.builder()
+                .addModule(mod1)
+                .addModule(mod2)
+                .build();
 
         Set<Object> registeredModuleIds = mapper.getRegisteredModuleIds();
         assertEquals(2, registeredModuleIds.size());
@@ -328,6 +333,20 @@ public void testGetRegisteredModules()
         // 01-Jul-2019, [databind#2374]: verify empty list is fine
         mapper = new ObjectMapper();
         assertEquals(0, mapper.getRegisteredModuleIds().size());
+
+        // 07-Jun-2021, tatu [databind#3110] Casual SimpleModules not returned
+        //     as registered
+        mapper = JsonMapper.builder()
+                .addModule(new SimpleModule())
+                .build();
+        assertEquals(0, mapper.getRegisteredModuleIds().size());
+
+        // But named ones are
+        mapper = JsonMapper.builder()
+                .addModule(new SimpleModule("VerySpecialModule"))
+                .build();
+        assertEquals(Collections.singleton("VerySpecialModule"),
+                mapper.getRegisteredModuleIds());
     }
 
     /*