Introduces Attributes for ValueProviders

equalsverifier-16/src/test/java/nl/jqno/equalsverifier/internal/reflection/vintage/RecordObjectAccessorScramblingTest.java

@@ -5,10 +5,10 @@
 import static org.junit.jupiter.api.Assertions.assertNotSame;
 
 import java.lang.reflect.Constructor;
-import java.util.LinkedHashSet;
 import nl.jqno.equalsverifier.internal.reflection.JavaApiPrefabValues;
 import nl.jqno.equalsverifier.internal.reflection.TypeTag;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.CachedValueProvider;
+import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider.Attributes;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.VintageValueProvider;
 import nl.jqno.equalsverifier.internal.testhelpers.TestValueProviders;
 import org.junit.jupiter.api.BeforeEach;
@@ -17,7 +17,7 @@
 
 public class RecordObjectAccessorScramblingTest {
 
-    private static final LinkedHashSet<TypeTag> EMPTY_TYPE_STACK = new LinkedHashSet<>();
+    private static final Attributes EMPTY_ATTRIBUTES = Attributes.unlabeled();
     private CachedValueProvider cache;
     private FactoryCache factoryCache;
     private VintageValueProvider valueProvider;
@@ -66,7 +66,7 @@ private <T> RecordObjectAccessor<T> create(T object) {
     }
 
     private ObjectAccessor<Object> doScramble(Object object) {
-        return create(object).scramble(valueProvider, TypeTag.NULL, EMPTY_TYPE_STACK);
+        return create(object).scramble(valueProvider, TypeTag.NULL, EMPTY_ATTRIBUTES);
     }
 
     record Point(int x, int y) {}

equalsverifier-16/src/test/java/nl/jqno/equalsverifier/internal/reflection/vintage/RecordObjectAccessorTest.java

@@ -4,13 +4,13 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.lang.reflect.Constructor;
-import java.util.LinkedHashSet;
 import java.util.Objects;
 import nl.jqno.equalsverifier.internal.exceptions.ReflectionException;
 import nl.jqno.equalsverifier.internal.reflection.Instantiator;
 import nl.jqno.equalsverifier.internal.reflection.JavaApiPrefabValues;
 import nl.jqno.equalsverifier.internal.reflection.TypeTag;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.CachedValueProvider;
+import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider.Attributes;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.VintageValueProvider;
 import nl.jqno.equalsverifier.internal.testhelpers.ExpectedException;
 import nl.jqno.equalsverifier.internal.testhelpers.TestValueProviders;
@@ -21,7 +21,7 @@
 
 public class RecordObjectAccessorTest {
 
-    private static final LinkedHashSet<TypeTag> EMPTY_TYPE_STACK = new LinkedHashSet<>();
+    private static final Attributes EMPTY_ATTRIBUTES = Attributes.unlabeled();
     private Objenesis objenesis;
     private Object recordInstance;
 
@@ -83,7 +83,7 @@ public void fail_whenConstructorThrowsOnSomethingElse() {
             objenesis
         );
         ExpectedException
-            .when(() -> accessorFor(instance).scramble(vp, TypeTag.NULL, EMPTY_TYPE_STACK))
+            .when(() -> accessorFor(instance).scramble(vp, TypeTag.NULL, EMPTY_ATTRIBUTES))
             .assertThrows(ReflectionException.class)
             .assertMessageContains("Record:", "failed to run constructor", "prefab values");
     }

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/checkers/AbstractDelegationChecker.java

@@ -10,6 +10,7 @@
 import nl.jqno.equalsverifier.internal.reflection.TypeTag;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.SubjectCreator;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider;
+import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider.Attributes;
 import nl.jqno.equalsverifier.internal.util.*;
 
 public class AbstractDelegationChecker<T> implements Checker {
@@ -74,7 +75,7 @@ private void checkAbstractDelegationInFields() {
 
     private <U> Tuple<U> safelyGetTuple(TypeTag tag, String fieldName) {
         try {
-            return valueProvider.provideOrThrow(tag, fieldName);
+            return valueProvider.provideOrThrow(tag, Attributes.labeled(fieldName));
         } catch (Exception ignored) {
             // If it fails for some reason, any reason, just return null so we can skip the test.
             return null;

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/checkers/MapEntryHashCodeRequirementChecker.java

@@ -5,6 +5,7 @@
 import java.util.Map;
 import java.util.Objects;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider;
+import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider.Attributes;
 import nl.jqno.equalsverifier.internal.util.Configuration;
 import nl.jqno.equalsverifier.internal.util.Context;
 import nl.jqno.equalsverifier.internal.util.Formatter;
@@ -23,7 +24,7 @@ public MapEntryHashCodeRequirementChecker(Context<T> context) {
     public void check() {
         if (Map.Entry.class.isAssignableFrom(config.getType())) {
             Map.Entry<?, ?> e = valueProvider
-                .<Map.Entry<?, ?>>provideOrThrow(config.getTypeTag(), null)
+                .<Map.Entry<?, ?>>provideOrThrow(config.getTypeTag(), Attributes.unlabeled())
                 .getRed();
 
             int expectedHashCode = Objects.hashCode(e.getKey()) ^ Objects.hashCode(e.getValue());

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/checkers/fieldchecks/JpaLazyGetterFieldCheck.java

@@ -14,6 +14,7 @@
 import nl.jqno.equalsverifier.internal.reflection.annotations.SupportedAnnotations;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.SubjectCreator;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider;
+import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider.Attributes;
 import nl.jqno.equalsverifier.internal.util.Configuration;
 import nl.jqno.equalsverifier.internal.util.Context;
 import nl.jqno.equalsverifier.internal.util.Formatter;
@@ -64,7 +65,7 @@ public void execute(FieldProbe fieldProbe) {
         );
 
         TypeTag sub = new TypeTag(throwingGetterCreator(getterName));
-        Tuple<T> tuple = valueProvider.provideOrThrow(sub, fieldName);
+        Tuple<T> tuple = valueProvider.provideOrThrow(sub, Attributes.labeled(fieldName));
         T red1 = tuple.getRed();
         T red2 = tuple.getRedCopy();
 

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/checkers/fieldchecks/ReflexivityFieldCheck.java

@@ -13,6 +13,7 @@
 import nl.jqno.equalsverifier.internal.reflection.annotations.SupportedAnnotations;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.SubjectCreator;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider;
+import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider.Attributes;
 import nl.jqno.equalsverifier.internal.util.Configuration;
 import nl.jqno.equalsverifier.internal.util.Context;
 import nl.jqno.equalsverifier.internal.util.Formatter;
@@ -80,7 +81,7 @@ private void checkValueReflexivity(FieldProbe probe) {
         String fieldName = field.getName();
         TypeTag tag = TypeTag.of(field, typeTag);
         Tuple<?> tuple = valueProvider
-            .provide(tag, fieldName)
+            .provide(tag, Attributes.labeled(fieldName))
             .orElseThrow(() -> new NoValueException(tag, fieldName));
 
         Object left = subjectCreator.withFieldSetTo(field, tuple.getRed());

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/checkers/fieldchecks/StringFieldCheck.java

@@ -8,6 +8,7 @@
 import nl.jqno.equalsverifier.internal.reflection.TypeTag;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.SubjectCreator;
 import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider;
+import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider.Attributes;
 import nl.jqno.equalsverifier.internal.util.CachedHashCodeInitializer;
 import nl.jqno.equalsverifier.internal.util.Formatter;
 
@@ -42,7 +43,7 @@ public void execute(FieldProbe fieldProbe) {
         if (String.class.equals(fieldProbe.getType()) && !fieldProbe.isStatic()) {
             TypeTag string = new TypeTag(String.class);
             String red = valueProvider
-                .<String>provideOrThrow(string, fieldProbe.getName())
+                .<String>provideOrThrow(string, Attributes.labeled(fieldProbe.getName()))
                 .getRed();
 
             final T reference;

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

@@ -39,8 +39,8 @@ public boolean contains(TypeTag tag, String label) {
      */
     @SuppressWarnings("unchecked")
     @Override
-    public <T> Optional<Tuple<T>> provide(TypeTag tag, String label) {
-        Key key = Key.of(tag, label);
+    public <T> Optional<Tuple<T>> provide(TypeTag tag, Attributes attributes) {
+        Key key = Key.of(tag, attributes.label);
         if (cache.containsKey(key)) {
             return Optional.of((Tuple<T>) cache.get(key));
         }

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

@@ -42,15 +42,15 @@ public void register(ValueProvider... valueProviders) {
 
     /** {@inheritDoc} */
     @Override
-    public <T> Optional<Tuple<T>> provide(TypeTag tag, String label) {
+    public <T> Optional<Tuple<T>> provide(TypeTag tag, Attributes attributes) {
         Optional<Tuple<T>> result = providers
             .stream()
-            .map(vp -> vp.<T>provide(tag, label))
+            .map(vp -> vp.<T>provide(tag, attributes))
             .filter(Optional::isPresent)
             .findFirst()
             .orElse(Optional.empty());
 
-        result.ifPresent(r -> cache.put(tag, label, r));
+        result.ifPresent(r -> cache.put(tag, attributes.label, r));
         return result;
     }
 }

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

@@ -6,6 +6,7 @@
 import java.util.Map;
 import nl.jqno.equalsverifier.internal.exceptions.ModuleException;
 import nl.jqno.equalsverifier.internal.reflection.*;
+import nl.jqno.equalsverifier.internal.reflection.instantiation.ValueProvider.Attributes;
 import nl.jqno.equalsverifier.internal.util.Configuration;
 import nl.jqno.equalsverifier.internal.util.Rethrow;
 import org.objenesis.Objenesis;
@@ -237,7 +238,10 @@ private FieldIterable nonSuperFields() {
     private Tuple<?> valuesFor(Field f) {
         try {
             TypeTag fieldTag = TypeTag.of(f, typeTag);
-            Tuple<?> tuple = valueProvider.provideOrThrow(fieldTag, f.getName());
+            Tuple<?> tuple = valueProvider.provideOrThrow(
+                fieldTag,
+                Attributes.labeled(f.getName())
+            );
             return tuple;
         } catch (ModuleException e) {
             throw new ModuleException(

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

@@ -1,5 +1,6 @@
 package nl.jqno.equalsverifier.internal.reflection.instantiation;
 
+import java.util.LinkedHashSet;
 import java.util.Optional;
 import nl.jqno.equalsverifier.internal.exceptions.NoValueException;
 import nl.jqno.equalsverifier.internal.reflection.Tuple;
@@ -21,26 +22,78 @@ public interface ValueProvider {
      *
      * @param <T> The returned tuple will have this generic type.
      * @param tag A description of the desired type, including generic parameters.
-     * @param label Returns only the value assigned to the given label, or if label is null,
-     *      returns the value that's not assigned to any label.
+     * @param attributes Provides metadata needed to provide a value.
      * @return A tuple of two different values of the given type, or an empty Optional if none
      *      could be found.
      */
-    <T> Optional<Tuple<T>> provide(TypeTag tag, String label);
+    <T> Optional<Tuple<T>> provide(TypeTag tag, Attributes attributes);
 
     /**
      * Returns a tuple of prefabricated values of the specified type, or, if none exists, throws a
      * NoValueException.
      *
      * @param <T> The returned tuple will have this generic type.
      * @param tag A description of the desired type, including generic parameters.
-     * @param label Returns only the value assigned to the given label, or if label is null,
-     *      returns the value that's not assigned to any label.
+     * @param attributes Provides metadata needed to provide a value.
      * @return A tuple of two different values of the given type, or an empty Optional if none
      *      could be found.
      * @throws NoValueException if no value could be found for the given tag.
      */
-    default <T> Tuple<T> provideOrThrow(TypeTag tag, String label) {
-        return this.<T>provide(tag, label).orElseThrow(() -> new NoValueException(tag));
+    default <T> Tuple<T> provideOrThrow(TypeTag tag, Attributes attributes) {
+        return this.<T>provide(tag, attributes).orElseThrow(() -> new NoValueException(tag));
+    }
+
+    /**
+     * Container for metadata needed to provide values.
+     */
+    public static final class Attributes {
+
+        /**
+         * Values can be assigned to a label; if one is specified, ValueProvider returns the value
+         * assigned to it (or falls back to the value assigned to a null label). If label is null,
+         * it immediately returns the value assigned to the null label.
+         */
+        public final String label;
+        /**
+         * Keeps track of recursion.
+         */
+        public final LinkedHashSet<TypeTag> typeStack;
+
+        /** Private constructor. Use the factories instead. */
+        private Attributes(String label, LinkedHashSet<TypeTag> typeStack) {
+            this.label = label;
+            this.typeStack = typeStack;
+        }
+
+        /**
+         * Don't use a label when providing a value.
+         *
+         * @return An Attributes object with no label.
+         */
+        public static Attributes unlabeled() {
+            return new Attributes(null, new LinkedHashSet<>());
+        }
+
+        /**
+         * Use a label when providing a value.
+         *
+         * @param label The label to use.
+         * @return An Attributes object with the given label.
+         */
+        public static Attributes labeled(String label) {
+            return new Attributes(label, new LinkedHashSet<>());
+        }
+
+        /**
+         * Clones the internal typeStack and adds a type to it.
+         *
+         * @param tag A type to add to the recursion checker.
+         * @return A new Attributes object with a type added to its typeStack.
+         */
+        public Attributes cloneAndAdd(TypeTag tag) {
+            LinkedHashSet<TypeTag> clone = new LinkedHashSet<>(typeStack);
+            clone.add(tag);
+            return new Attributes(label, clone);
+        }
     }
 }