Fix #53 (#113)

Author: cowtowncoder

VERSION.txt

@@ -5,7 +5,8 @@ Release notes:
 
 1.8.0 (not yet released)
 
--
+#53: Allow for subtype resolution with unknown generics
+ (reported by Carsten W, @CarstenWickner)
 
 1.7.1 (26-Sep-2025)
 

src/main/java/com/fasterxml/classmate/TypeResolver.java

@@ -422,10 +422,28 @@ private ResolvedType _constructType(ClassStack context, Class<?> rawType, TypeBi
             ResolvedType elementType = _fromAny(context, rawType.getComponentType(), typeBindings);
             return new ResolvedArrayType(rawType, typeBindings, elementType);
         }
-        // Work-around/fix for [#33]: if the type has no type parameters, don't include
-        // typeBindings in the ResolvedType
-        if (!typeBindings.isEmpty() && rawType.getTypeParameters().length == 0) {
-            typeBindings = TypeBindings.emptyBindings();
+        final TypeVariable<?>[] rawTypeParameters = rawType.getTypeParameters();
+        // [classmate#53]: Handle raw generic types - resolve type parameters to their bounds
+        if (typeBindings.isEmpty()) {
+            if (rawTypeParameters.length > 0) {
+                ResolvedType[] types = new ResolvedType[rawTypeParameters.length];
+                for (int i = 0; i < rawTypeParameters.length; ++i) {
+                    // Resolve each type parameter to its bound (similar to _fromVariable)
+                    TypeVariable<?> var = rawTypeParameters[i];
+                    String name = var.getName();
+                    // Avoid self-reference cycles by marking as unbound during resolution
+                    TypeBindings tempBindings = typeBindings.withUnboundVariable(name);
+                    Type[] bounds = var.getBounds();
+                    types[i] = _fromAny(context, bounds[0], tempBindings);
+                }
+                typeBindings = TypeBindings.create(rawType, types);
+            }
+        } else {
+            // Work-around/fix for [classmate#33]: if the type has no type parameters,
+            // don't include typeBindings in the ResolvedType
+            if (rawTypeParameters.length == 0) {
+                typeBindings = TypeBindings.emptyBindings();
+            }
         }
         // For other types super interfaces are needed...
         if (rawType.isInterface()) {

src/test/java/com/fasterxml/classmate/TestTypeResolver53.java

@@ -0,0 +1,76 @@
+package com.fasterxml.classmate;
+
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Map;
+
+import com.fasterxml.classmate.BaseTest;
+import com.fasterxml.classmate.ResolvedType;
+import com.fasterxml.classmate.TypeResolver;
+
+// for [classmate#53]: Raw Comparator
+public class TestTypeResolver53 extends BaseTest
+{
+    @SuppressWarnings("rawtypes")
+    static abstract class Comparator53 implements Comparator { }
+
+    @SuppressWarnings("rawtypes")
+    static abstract class Map53 implements Map { }
+
+    @SuppressWarnings("rawtypes")
+    static abstract class BoundedComparable<T extends Number> implements Comparable { }
+
+    @SuppressWarnings("rawtypes")
+    static abstract class BoundedRaw extends BoundedComparable { }
+
+    static abstract class NestedRaw extends java.util.ArrayList<Map> { }
+
+    protected final TypeResolver RESOLVER = new TypeResolver();
+
+    // [classmate#53] Problem with Raw types - single type parameter
+    public void testResolvingRawType() {
+        ResolvedType rt = RESOLVER.resolve(Comparator53.class);
+        List<ResolvedType> params = rt.typeParametersFor(Comparator.class);
+        assertEquals(Arrays.asList(RESOLVER.resolve(Object.class)),
+                params);
+    }
+
+    // [classmate#53] Raw type with multiple type parameters (Map<K,V>)
+    public void testRawTypeMultipleParameters() {
+        ResolvedType rt = RESOLVER.resolve(Map53.class);
+        List<ResolvedType> params = rt.typeParametersFor(Map.class);
+        assertEquals(Arrays.asList(
+                RESOLVER.resolve(Object.class),
+                RESOLVER.resolve(Object.class)),
+                params);
+    }
+
+    // [classmate#53] Raw type with bounded type parameter
+    public void testRawTypeWithBoundedParameter() {
+        ResolvedType rt = RESOLVER.resolve(BoundedRaw.class);
+        List<ResolvedType> params = rt.typeParametersFor(Comparable.class);
+        // BoundedComparable<T extends Number> implements Comparable<T>, used raw
+        // Type parameter T has bound Number, so should resolve to Number
+        assertEquals(Arrays.asList(RESOLVER.resolve(Number.class)),
+                params);
+    }
+
+    // [classmate#53] Nested raw types (List<Map> where Map is raw)
+    public void testNestedRawType() {
+        ResolvedType rt = RESOLVER.resolve(NestedRaw.class);
+        List<ResolvedType> params = rt.typeParametersFor(java.util.ArrayList.class);
+        assertEquals(1, params.size());
+
+        // The type parameter should be Map (raw), which should have its own parameters
+        ResolvedType mapType = params.get(0);
+        assertEquals(Map.class, mapType.getErasedType());
+
+        // The raw Map should have Object,Object as its type parameters
+        List<ResolvedType> mapParams = mapType.getTypeParameters();
+        assertEquals(Arrays.asList(
+                RESOLVER.resolve(Object.class),
+                RESOLVER.resolve(Object.class)),
+                mapParams);
+    }
+}