Simplify objenesis cache reset to improve error message with self-ref…

…erring generics

CHANGELOG.md

@@ -15,8 +15,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- The error message in some edge cases involving complex generics and abstract classes is now improved. ([Issue 983](https://github.com/jqno/equalsverifier/issues/983))
 - The line in the error message that shows the version of EqualsVerifier and the JDK, now also indicates whether EqualsVerifier runs on the classpath or the modulepath.
 
+### Deprecated
+
+- `withResetCaches()` was once needed for use in Quarkus, but caches are now reset automatically on every run.
+
 ## [3.16.1] - 2024-04-03
 
 ### Fixed

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/ConfiguredEqualsVerifier.java

@@ -12,7 +12,6 @@
 import nl.jqno.equalsverifier.internal.prefabvalues.FactoryCache;
 import nl.jqno.equalsverifier.internal.reflection.PackageScanner;
 import nl.jqno.equalsverifier.internal.util.ListBuilders;
-import nl.jqno.equalsverifier.internal.util.ObjenesisWrapper;
 import nl.jqno.equalsverifier.internal.util.PrefabValuesApi;
 import nl.jqno.equalsverifier.internal.util.Validations;
 
@@ -104,10 +103,13 @@ public ConfiguredEqualsVerifier withFieldnameToGetterConverter(
         return this;
     }
 
-    /** {@inheritDoc} */
+    /**
+     * {@inheritDoc}
+     * @deprecated No longer needed; this happens automatically.
+     */
+    @Deprecated
     @Override
     public ConfiguredEqualsVerifier withResetCaches() {
-        ObjenesisWrapper.reset();
         return this;
     }
 

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/api/EqualsVerifierApi.java

@@ -90,6 +90,8 @@ public interface EqualsVerifierApi<T> {
      * that would normally be equal, to be unequal, because their ClassLoaders don't match.
      *
      * @return {@code this}, for easy method chaining.
+     * @deprecated No longer needed; this happens automatically.
      */
+    @Deprecated
     EqualsVerifierApi<T> withResetCaches();
 }

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/api/MultipleTypeEqualsVerifierApi.java

@@ -14,7 +14,6 @@
 import nl.jqno.equalsverifier.internal.util.ErrorMessage;
 import nl.jqno.equalsverifier.internal.util.Formatter;
 import nl.jqno.equalsverifier.internal.util.ListBuilders;
-import nl.jqno.equalsverifier.internal.util.ObjenesisWrapper;
 import nl.jqno.equalsverifier.internal.util.Validations;
 
 /**
@@ -80,10 +79,13 @@ public MultipleTypeEqualsVerifierApi withFieldnameToGetterConverter(
         return this;
     }
 
-    /** {@inheritDoc} */
+    /**
+     * {@inheritDoc}
+     * @deprecated No longer needed; this happens automatically.
+     */
+    @Deprecated
     @Override
     public MultipleTypeEqualsVerifierApi withResetCaches() {
-        ObjenesisWrapper.reset();
         return this;
     }
 

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/api/SingleTypeEqualsVerifierApi.java

@@ -328,10 +328,13 @@ public SingleTypeEqualsVerifierApi<T> withLombokCachedHashCode(T example) {
         return this;
     }
 
-    /** {@inheritDoc} */
+    /**
+     * {@inheritDoc}
+     * @deprecated No longer needed; this happens automatically.
+     */
+    @Deprecated
     @Override
     public SingleTypeEqualsVerifierApi<T> withResetCaches() {
-        ObjenesisWrapper.reset();
         return this;
     }
 
@@ -402,6 +405,7 @@ private String buildErrorMessage(String description, boolean showUrl) {
     }
 
     private void performVerification() {
+        ObjenesisWrapper.reset();
         if (type.isEnum() || type.isInterface()) {
             return;
         }

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/reflection/FieldModifier.java

@@ -139,9 +139,13 @@ private void wrappedChange(FieldChanger changer) throws IllegalAccessException {
         try {
             changer.change();
         } catch (IllegalArgumentException e) {
-            if (e.getMessage().startsWith("Can not set")) {
+            String msg = e.getMessage();
+            if (msg.startsWith("Can not set") || msg.startsWith("Can not get")) {
                 throw new ReflectionException(
-                    "Reflection error: perhaps a ClassLoader problem?\nTry re-running with #withResetCaches()",
+                    "Reflection error: try adding a prefab value for field " +
+                    field.getName() +
+                    " of type " +
+                    field.getType().getName(),
                     e
                 );
             } else {

equalsverifier-core/src/test/java/nl/jqno/equalsverifier/integration/extended_contract/GenericTypesTest.java

@@ -8,6 +8,8 @@
 import java.util.concurrent.atomic.AtomicReferenceArray;
 import java.util.function.Supplier;
 import nl.jqno.equalsverifier.EqualsVerifier;
+import nl.jqno.equalsverifier.Warning;
+import nl.jqno.equalsverifier.internal.testhelpers.ExpectedException;
 import nl.jqno.equalsverifier.testhelpers.types.Point;
 import org.junit.jupiter.api.Test;
 
@@ -93,6 +95,32 @@ public void succeed_whenClassHasTypeVariableThatExtendsSomethingThatSupersSometh
         EqualsVerifier.forClass(TypeVariableExtendsWithSuperContainer.class).verify();
     }
 
+    @Test
+    public void failGracefully_whenClassHasASelfReferenceGenericParameter() {
+        ExpectedException
+            .when(() -> EqualsVerifier.forClass(SelfReferringGenericType.class).verify())
+            .assertFailure()
+            .assertMessageContains(
+                "Reflection error",
+                "try adding a prefab value",
+                "field wrapped",
+                "of type " + SelfReferringGenericType.class.getName()
+            );
+    }
+
+    @Test
+    public void succeed_whenClassHasASelfReferenceGenericParameter_givenPrefabValues() {
+        EqualsVerifier
+            .forClass(SelfReferringGenericType.class)
+            .withPrefabValues(
+                SelfReferringGenericType.class,
+                new SelfReferringGenericType<>(1),
+                new SelfReferringGenericType<>(2)
+            )
+            .suppress(Warning.NONFINAL_FIELDS)
+            .verify();
+    }
+
     static final class JavaGenericTypeContainer {
 
         private final Optional<Point> optional;
@@ -704,4 +732,31 @@ public int hashCode() {
             return defaultHashCode(this);
         }
     }
+
+    public static class SelfReferringGenericType<T extends SelfReferringGenericType<T>> {
+
+        private T wrapped;
+
+        // Everything below is boilerplate to be able to run the tests; the bit above this comment is what matters
+
+        private final int i;
+
+        public SelfReferringGenericType(int i) {
+            this.i = i;
+        }
+
+        @Override
+        public final boolean equals(Object obj) {
+            if (!(obj instanceof SelfReferringGenericType)) {
+                return false;
+            }
+            SelfReferringGenericType<?> other = (SelfReferringGenericType<?>) obj;
+            return i == other.i && Objects.equals(wrapped, other.wrapped);
+        }
+
+        @Override
+        public final int hashCode() {
+            return Objects.hash(i, wrapped);
+        }
+    }
 }

equalsverifier-core/src/test/java/nl/jqno/equalsverifier/integration/operational/WithResetCachesTest.java

@@ -5,32 +5,15 @@
 import nl.jqno.equalsverifier.EqualsVerifier;
 import nl.jqno.equalsverifier.internal.util.ObjenesisWrapper;
 import nl.jqno.equalsverifier.testhelpers.packages.correct.A;
-import nl.jqno.equalsverifier.testhelpers.packages.correct.B;
 import org.junit.jupiter.api.Test;
 import org.objenesis.Objenesis;
 
 public class WithResetCachesTest {
 
     @Test
-    public void single() {
+    public void resetObjenesisCacheOnEachRun() {
         Objenesis original = ObjenesisWrapper.getObjenesis();
-        EqualsVerifier.forClass(A.class).withResetCaches();
-        Objenesis reset = ObjenesisWrapper.getObjenesis();
-        assertNotEquals(original, reset);
-    }
-
-    @Test
-    public void multiple() {
-        Objenesis original = ObjenesisWrapper.getObjenesis();
-        EqualsVerifier.forClasses(A.class, B.class).withResetCaches();
-        Objenesis reset = ObjenesisWrapper.getObjenesis();
-        assertNotEquals(original, reset);
-    }
-
-    @Test
-    public void configured() {
-        Objenesis original = ObjenesisWrapper.getObjenesis();
-        EqualsVerifier.configure().withResetCaches();
+        EqualsVerifier.forClass(A.class).verify();
         Objenesis reset = ObjenesisWrapper.getObjenesis();
         assertNotEquals(original, reset);
     }

equalsverifier-core/src/test/java/nl/jqno/equalsverifier/internal/reflection/FieldModifierTest.java

@@ -7,11 +7,9 @@
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
-import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.lang.reflect.Field;
-import nl.jqno.equalsverifier.internal.exceptions.ReflectionException;
 import nl.jqno.equalsverifier.internal.prefabvalues.FactoryCache;
 import nl.jqno.equalsverifier.internal.prefabvalues.JavaApiPrefabValues;
 import nl.jqno.equalsverifier.internal.prefabvalues.PrefabValues;
@@ -333,20 +331,6 @@ public void addPrefabArrayValues() {
         assertEquals(RED_NEW_POINT, foo.points[0]);
     }
 
-    @Test
-    public void shouldDetectClassloaderIssue() throws Exception {
-        // We're faking the problem by using two entirely different classes.
-        // In reality, this problem comes up with the same types, but loaded by different class loaders,
-        // which makes them effectively different types as well. This was hard to fake in a test.
-        Object foo = new ObjectContainer();
-        Field field = PrimitiveContainer.class.getField("field");
-        FieldModifier fm = FieldModifier.of(field, foo);
-
-        ReflectionException e = assertThrows(ReflectionException.class, () -> fm.set(new Object()));
-
-        assertTrue(e.getMessage().contains("perhaps a ClassLoader problem?"));
-    }
-
     private void setField(Object object, String fieldName, Object value) {
         getAccessorFor(object, fieldName).set(value);
     }