Fixes generics issue in withPrefabValuesForField()

jqno · Nov 6, 2024 · 8b2c31b · 8b2c31b
1 parent ebe648f
commit 8b2c31b
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Showing 4 changed files with 89 additions and 49 deletions.
diff --git a/equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/util/PrefabValuesApi.java b/equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/util/PrefabValuesApi.java
@@ -1,5 +1,6 @@
 package nl.jqno.equalsverifier.internal.util;
 
+import java.lang.reflect.Field;
 import nl.jqno.equalsverifier.Func.Func1;
 import nl.jqno.equalsverifier.Func.Func2;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.GenericPrefabValueProvider.GenericFactories;
@@ -42,10 +43,11 @@ public static <T> void addPrefabValuesForField(
         T red,
         T blue
     ) {
-        Class<T> type = (Class<T>) red.getClass();
+        Field field = getField(enclosingType, fieldName);
+        Class<T> type = (Class<T>) field.getType();
 
         Validations.validateRedAndBluePrefabValues(type, red, blue);
-        Validations.validateFieldTypeMatches(enclosingType, fieldName, red.getClass());
+        Validations.validateFieldTypeMatches(field, red.getClass());
 
         if (type.isArray()) {
             provider.register(type, fieldName, red, blue, red);
@@ -60,6 +62,20 @@ public static <T> void addPrefabValuesForField(
         }
     }
 
+    private static Field getField(Class<?> type, String fieldName) {
+        try {
+            return type.getDeclaredField(fieldName);
+        } catch (NoSuchFieldException e) {
+            throw new IllegalStateException(
+                "Precondition: class " +
+                type.getSimpleName() +
+                " does not contain field " +
+                fieldName +
+                "."
+            );
+        }
+    }
+
     public static <T> void addGenericPrefabValues(
         GenericFactories factories,
         Class<T> otherType,

diff --git a/equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/util/Validations.java b/equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/util/Validations.java
@@ -88,33 +88,21 @@ public static <T> void validateRedAndBluePrefabValues(Class<T> type, T red, T bl
         );
     }
 
-    public static <T> void validateFieldTypeMatches(
-        Class<T> container,
-        String fieldName,
-        Class<?> fieldType
-    ) {
-        try {
-            Field f = container.getDeclaredField(fieldName);
-            boolean typeCompatible = f.getType().isAssignableFrom(fieldType);
-            boolean wrappingCompatible = fieldType.equals(
-                PrimitiveMappers.PRIMITIVE_OBJECT_MAPPER.get(f.getType())
-            );
-            validate(
-                !typeCompatible && !wrappingCompatible,
-                "Prefab values for field " +
-                fieldName +
-                " should be of type " +
-                f.getType().getSimpleName() +
-                " but are " +
-                fieldType.getSimpleName() +
-                "."
-            );
-        } catch (NoSuchFieldException e) {
-            validate(
-                false,
-                "Class " + container.getSimpleName() + " has no field named " + fieldName + "."
-            );
-        }
+    public static <T> void validateFieldTypeMatches(Field field, Class<?> realFieldType) {
+        boolean typeCompatible = field.getType().isAssignableFrom(realFieldType);
+        boolean wrappingCompatible = realFieldType.equals(
+            PrimitiveMappers.PRIMITIVE_OBJECT_MAPPER.get(field.getType())
+        );
+        validate(
+            !typeCompatible && !wrappingCompatible,
+            "Prefab values for field " +
+            field.getName() +
+            " should be of type " +
+            field.getType().getSimpleName() +
+            " but are " +
+            realFieldType.getSimpleName() +
+            "."
+        );
     }
 
     public static <T> void validateGenericPrefabValues(Class<T> type, int arity) {

diff --git a/...est/java/nl/jqno/equalsverifier/integration/operational/WithPrefabValuesForFieldTest.java b/...est/java/nl/jqno/equalsverifier/integration/operational/WithPrefabValuesForFieldTest.java
@@ -177,6 +177,21 @@ public void succeed_whenClassContainsSomethingThatAllowsSubclassesAndASubclassIs
             .verify();
     }
 
+    @Test
+    public void succeed_whenClassContainsAGenericInterfaceThatRefersToItself() {
+        DifficultGeneric one = new DifficultGeneric(new ArrayList<>());
+        DifficultGeneric two = new DifficultGeneric(null);
+
+        EqualsVerifier
+            .forClass(DifficultGeneric.class)
+            .withPrefabValuesForField(
+                "list",
+                Collections.singletonList(one),
+                Collections.singletonList(two)
+            )
+            .verify();
+    }
+
     static final class SinglePrecondition {
 
         private final FinalPoint point;
@@ -308,4 +323,27 @@ public int hashCode() {
             return Objects.hash(list);
         }
     }
+
+    public final class DifficultGeneric {
+
+        private final List<DifficultGeneric> list;
+
+        public DifficultGeneric(List<DifficultGeneric> list) {
+            this.list = list;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (!(obj instanceof DifficultGeneric)) {
+                return false;
+            }
+            DifficultGeneric other = (DifficultGeneric) obj;
+            return Objects.equals(list, other.list);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(list);
+        }
+    }
 }
diff --git a/equalsverifier-core/src/test/java/nl/jqno/equalsverifier/internal/util/ValidationsTest.java b/equalsverifier-core/src/test/java/nl/jqno/equalsverifier/internal/util/ValidationsTest.java
@@ -4,10 +4,8 @@
 import static org.junit.jupiter.api.Assertions.assertAll;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.List;
+import java.lang.reflect.Field;
+import java.util.*;
 import nl.jqno.equalsverifier.internal.testhelpers.ExpectedException;
 import org.junit.jupiter.api.Test;
 
@@ -25,8 +23,7 @@ public void validateFieldTypeMatches_shouldFailOnWrongType() {
                 ExpectedException
                     .when(() ->
                         Validations.validateFieldTypeMatches(
-                            TestContainer.class,
-                            "listField",
+                            getField(TestContainer.class, "listField"),
                             HashSet.class
                         )
                     )
@@ -37,8 +34,7 @@ public void validateFieldTypeMatches_shouldFailOnWrongType() {
                 ExpectedException
                     .when(() ->
                         Validations.validateFieldTypeMatches(
-                            TestContainer.class,
-                            "objectField",
+                            getField(TestContainer.class, "objectField"),
                             int.class
                         )
                     )
@@ -49,8 +45,7 @@ public void validateFieldTypeMatches_shouldFailOnWrongType() {
                 ExpectedException
                     .when(() ->
                         Validations.validateFieldTypeMatches(
-                            TestContainer.class,
-                            "charsField",
+                            getField(TestContainer.class, "charsField"),
                             Character.class
                         )
                     )
@@ -67,8 +62,7 @@ public void validateFieldTypeMatches_shouldAllowSubTypes() {
                 assertDoesNotThrow(
                     () ->
                         Validations.validateFieldTypeMatches(
-                            TestContainer.class,
-                            "listField",
+                            getField(TestContainer.class, "listField"),
                             ArrayList.class
                         ),
                     "Should allow ArrayList as a List"
@@ -77,8 +71,7 @@ public void validateFieldTypeMatches_shouldAllowSubTypes() {
                 assertDoesNotThrow(
                     () ->
                         Validations.validateFieldTypeMatches(
-                            TestContainer.class,
-                            "objectField",
+                            getField(TestContainer.class, "objectField"),
                             Integer.class
                         ),
                     "Should allow Integer as an Object"
@@ -87,8 +80,7 @@ public void validateFieldTypeMatches_shouldAllowSubTypes() {
                 assertDoesNotThrow(
                     () ->
                         Validations.validateFieldTypeMatches(
-                            TestContainer.class,
-                            "charsField",
+                            getField(TestContainer.class, "charsField"),
                             String.class
                         ),
                     "Should allow String as a CharSequence"
@@ -103,8 +95,7 @@ public void validateFieldTypeMatches_shouldFailOnSuperTypes() {
                 ExpectedException
                     .when(() ->
                         Validations.validateFieldTypeMatches(
-                            TestContainer.class,
-                            "listField",
+                            getField(TestContainer.class, "listField"),
                             Collection.class
                         )
                     )
@@ -115,8 +106,7 @@ public void validateFieldTypeMatches_shouldFailOnSuperTypes() {
                 ExpectedException
                     .when(() ->
                         Validations.validateFieldTypeMatches(
-                            TestContainer.class,
-                            "charsField",
+                            getField(TestContainer.class, "charsField"),
                             Object.class
                         )
                     )
@@ -126,6 +116,14 @@ public void validateFieldTypeMatches_shouldFailOnSuperTypes() {
         );
     }
 
+    private Field getField(Class<?> type, String fieldName) {
+        try {
+            return type.getDeclaredField(fieldName);
+        } catch (NoSuchFieldException e) {
+            throw new AssertionError("Class " + type + " has no field " + fieldName);
+        }
+    }
+
     @SuppressWarnings("unused")
     private static final class TestContainer {