Supports dynamic subclasses of types with no package

jqno · Dec 2, 2022 · 281c99d · 281c99d
1 parent f40488d
commit 281c99d
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -17,6 +17,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Improved error message output for objects that throw exceptions in their `toString()` methods. ([Issue 716](https://github.com/jqno/equalsverifier/issues/716))
 
+### Fixed
+
+- Fix `ClassFormatError` when attempting to create a dynamic subclass for a class that has no package. ([Issue 638](https://github.com/jqno/equalsverifier/issues/638))
+
 ## [3.12] - 2022-11-30
 
 ### Added

diff --git a/...sverifier-core/src/main/java/nl/jqno/equalsverifier/internal/reflection/Instantiator.java b/...sverifier-core/src/main/java/nl/jqno/equalsverifier/internal/reflection/Instantiator.java
@@ -86,7 +86,7 @@ public static synchronized <S> Class<S> giveDynamicSubclass(
         String namePrefix = isSystemClass ? FALLBACK_PACKAGE_NAME : getPackageName(superclass);
         String name =
             namePrefix +
-            "." +
+            (namePrefix.isEmpty() ? "" : ".") +
             superclass.getSimpleName() +
             "$$DynamicSubclass$" +
             Integer.toHexString(superclass.hashCode()) +

diff --git a/...ifier-core/src/test/java/nl/jqno/equalsverifier/internal/reflection/InstantiatorTest.java b/...ifier-core/src/test/java/nl/jqno/equalsverifier/internal/reflection/InstantiatorTest.java
@@ -7,7 +7,9 @@
 
 import java.lang.reflect.Field;
 import java.util.List;
+import net.bytebuddy.ByteBuddy;
 import net.bytebuddy.description.modifier.Visibility;
+import net.bytebuddy.dynamic.scaffold.TypeValidation;
 import nl.jqno.equalsverifier.testhelpers.types.ColorBlindColorPoint;
 import nl.jqno.equalsverifier.testhelpers.types.FinalPoint;
 import nl.jqno.equalsverifier.testhelpers.types.Point;
@@ -104,4 +106,16 @@ class Super {}
         Field f = sub.getDeclaredField("dynamicField");
         assertNotNull(f);
     }
+
+    @Test
+    public void giveDynamicSubclassForClassWithNoPackage() {
+        Class<?> type = new ByteBuddy()
+            .with(TypeValidation.DISABLED)
+            .subclass(Object.class)
+            .name("NoPackage")
+            .make()
+            .load(getClass().getClassLoader())
+            .getLoaded();
+        Instantiator.giveDynamicSubclass(type, "X", b -> b);
+    }
 }