fix: equals and hashcode of several classes

src/main/java/dev/openfeature/sdk/AbstractStructure.java

@@ -11,7 +11,7 @@ abstract class AbstractStructure implements Structure {
 
     @Override
     public boolean isEmpty() {
-        return attributes == null || attributes.size() == 0;
+        return attributes == null || attributes.isEmpty();
     }
 
     AbstractStructure() {
@@ -46,4 +46,46 @@ public Map<String, Object> asObjectMap() {
                         (accumulated, entry) -> accumulated.put(entry.getKey(), convertValue(entry.getValue())),
                         HashMap::putAll);
     }
+
+    public boolean equals(final Object o) {
+        if (o == this) {
+            return true;
+        }
+        if (!(o instanceof AbstractStructure)) {
+            return false;
+        }
+        final AbstractStructure other = (AbstractStructure) o;
+        if (other.attributes == attributes) {
+            return true;
+        }
+        if (attributes == null || other.attributes == null) {
+            return false;
+        }
+        if (other.attributes.size() != attributes.size()) {
+            return false;
+        }
+
+        for (Map.Entry<String, Value> thisEntry : attributes.entrySet()) {
+            Value thisValue = thisEntry.getValue();
+            Value otherValue = other.attributes.get(thisEntry.getKey());
+            if (thisValue == null && otherValue == null) {
+                continue;
+            }
+            if (thisValue == null || otherValue == null) {
+                return false;
+            }
+            if (!thisValue.equals(otherValue)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    public int hashCode() {
+        if (attributes == null) {
+            return 0;
+        }
+        return attributes.hashCode();
+    }
 }

src/main/java/dev/openfeature/sdk/ImmutableContext.java

@@ -91,6 +91,23 @@ public EvaluationContext merge(EvaluationContext overridingContext) {
         return new ImmutableContext(attributes);
     }
 
+    @Override
+    public boolean equals(Object object) {
+        if (object == this) {
+            return true;
+        }
+        if (!(object instanceof ImmutableContext)) {
+            return false;
+        }
+        ImmutableContext other = (ImmutableContext) object;
+        return this.structure.equals(other.structure);
+    }
+
+    @Override
+    public int hashCode() {
+        return structure.hashCode();
+    }
+
     @SuppressWarnings("all")
     private static class DelegateExclusions {
         @ExcludeFromGeneratedCoverageReport

src/main/java/dev/openfeature/sdk/ImmutableMetadata.java

@@ -101,6 +101,42 @@ public boolean isEmpty() {
         return metadata.isEmpty();
     }
 
+    public boolean equals(final Object o) {
+        if (o == this) {
+            return true;
+        }
+        if (!(o instanceof ImmutableMetadata)) {
+            return false;
+        }
+        final ImmutableMetadata other = (ImmutableMetadata) o;
+        if (other.metadata == metadata) {
+            return true;
+        }
+        if (other.metadata.size() != metadata.size()) {
+            return false;
+        }
+
+        for (Map.Entry<String, Object> thisEntry : metadata.entrySet()) {
+            Object thisValue = thisEntry.getValue();
+            Object otherValue = other.metadata.get(thisEntry.getKey());
+            if (thisValue == null && otherValue == null) {
+                continue;
+            }
+            if (thisValue == null || otherValue == null) {
+                return false;
+            }
+            if (!thisValue.equals(otherValue)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    public int hashCode() {
+        return metadata.hashCode();
+    }
+
     /**
      * Obtain a builder for {@link ImmutableMetadata}.
      */

src/main/java/dev/openfeature/sdk/ImmutableStructure.java

@@ -6,7 +6,6 @@
 import java.util.Map.Entry;
 import java.util.Optional;
 import java.util.Set;
-import lombok.EqualsAndHashCode;
 import lombok.ToString;
 
 /**
@@ -18,7 +17,6 @@
  * not be modified after instantiation. All references are clones.
  */
 @ToString
-@EqualsAndHashCode
 @SuppressWarnings({"PMD.BeanMembersShouldSerialize", "checkstyle:MissingJavadocType"})
 public final class ImmutableStructure extends AbstractStructure {
 
@@ -38,7 +36,7 @@ public ImmutableStructure(Map<String, Value> attributes) {
         super(copyAttributes(attributes, null));
     }
 
-    protected ImmutableStructure(String targetingKey, Map<String, Value> attributes) {
+    ImmutableStructure(String targetingKey, Map<String, Value> attributes) {
         super(copyAttributes(attributes, targetingKey));
     }
 

src/main/java/dev/openfeature/sdk/MutableContext.java

@@ -6,7 +6,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
-import lombok.EqualsAndHashCode;
 import lombok.ToString;
 import lombok.experimental.Delegate;
 
@@ -17,7 +16,6 @@
  * be modified after instantiation.
  */
 @ToString
-@EqualsAndHashCode
 @SuppressWarnings("PMD.BeanMembersShouldSerialize")
 public class MutableContext implements EvaluationContext {
 
@@ -125,6 +123,23 @@ public EvaluationContext merge(EvaluationContext overridingContext) {
         return new MutableContext(attributes);
     }
 
+    @Override
+    public boolean equals(Object object) {
+        if (object == this) {
+            return true;
+        }
+        if (!(object instanceof MutableContext)) {
+            return false;
+        }
+        MutableContext other = (MutableContext) object;
+        return this.structure.equals(other.structure);
+    }
+
+    @Override
+    public int hashCode() {
+        return structure.hashCode();
+    }
+
     /**
      * Hidden class to tell Lombok not to copy these methods over via delegation.
      */

src/main/java/dev/openfeature/sdk/MutableStructure.java

@@ -5,7 +5,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import lombok.EqualsAndHashCode;
 import lombok.ToString;
 
 /**
@@ -15,7 +14,6 @@
  * be modified after instantiation.
  */
 @ToString
-@EqualsAndHashCode
 @SuppressWarnings({"PMD.BeanMembersShouldSerialize", "checkstyle:MissingJavadocType"})
 public class MutableStructure extends AbstractStructure {
 

src/main/java/dev/openfeature/sdk/Value.java

@@ -7,7 +7,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
-import lombok.EqualsAndHashCode;
 import lombok.SneakyThrows;
 import lombok.ToString;
 
@@ -17,7 +16,6 @@
  * This intermediate representation provides a good medium of exchange.
  */
 @ToString
-@EqualsAndHashCode
 @SuppressWarnings({"PMD.BeanMembersShouldSerialize", "checkstyle:MissingJavadocType", "checkstyle:NoFinalizer"})
 public class Value implements Cloneable {
 
@@ -316,4 +314,31 @@ public static Value objectToValue(Object object) {
             throw new TypeMismatchError("Flag value " + object + " had unexpected type " + object.getClass() + ".");
         }
     }
+
+    /**
+     * Returns true iff {@code this} is equal to {@code o}, or if both objects represent the same data.
+     * @param o the other object
+     * @return true iff both objects are equal or represent the same data
+     */
+    public boolean equals(final Object o) {
+        if (o == this) {
+            return true;
+        }
+        if (!(o instanceof Value)) {
+            return false;
+        }
+        final Value other = (Value) o;
+        return innerObject.equals(other.innerObject);
+    }
+
+    /**
+     * Returns the `hashCode` of the underlying data, or 0 if {@link Value#isNull()} returns true.
+     * @return the hash code
+     */
+    public int hashCode() {
+        if (innerObject == null) {
+            return 0;
+        }
+        return innerObject.hashCode();
+    }
 }

src/test/java/dev/openfeature/sdk/ImmutableContextTest.java

@@ -3,6 +3,7 @@
 import static dev.openfeature.sdk.EvaluationContext.TARGETING_KEY;
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.Collections;
@@ -133,4 +134,31 @@ void mergeShouldRetainItsSubkeysWhenOverridingContextHasNoTargetingKey() {
         Structure value = key1.asStructure();
         assertArrayEquals(new Object[] {"key1_1"}, value.keySet().toArray());
     }
+
+    @DisplayName("Two different MutableContext objects with the different contents are not considered equal")
+    @Test
+    void unequalImmutableContextsAreNotEqual() {
+        final Map<String, Value> attributes = new HashMap<>();
+        attributes.put("key1", new Value("val1"));
+        final ImmutableContext ctx = new ImmutableContext(attributes);
+
+        final Map<String, Value> attributes2 = new HashMap<>();
+        final ImmutableContext ctx2 = new ImmutableContext(attributes2);
+
+        assertNotEquals(ctx, ctx2);
+    }
+
+    @DisplayName("Two different MutableContext objects with the same content are considered equal")
+    @Test
+    void equalImmutableContextsAreEqual() {
+        final Map<String, Value> attributes = new HashMap<>();
+        attributes.put("key1", new Value("val1"));
+        final ImmutableContext ctx = new ImmutableContext(attributes);
+
+        final Map<String, Value> attributes2 = new HashMap<>();
+        attributes2.put("key1", new Value("val1"));
+        final ImmutableContext ctx2 = new ImmutableContext(attributes2);
+
+        assertEquals(ctx, ctx2);
+    }
 }

src/test/java/dev/openfeature/sdk/ImmutableMetadataTest.java

@@ -0,0 +1,28 @@
+package dev.openfeature.sdk;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+
+import org.junit.jupiter.api.Test;
+
+class ImmutableMetadataTest {
+    @Test
+    void unequalImmutableMetadataAreUnequal() {
+        ImmutableMetadata i1 =
+                ImmutableMetadata.builder().addString("key1", "value1").build();
+        ImmutableMetadata i2 =
+                ImmutableMetadata.builder().addString("key1", "value2").build();
+
+        assertNotEquals(i1, i2);
+    }
+
+    @Test
+    void equalImmutableMetadataAreEqual() {
+        ImmutableMetadata i1 =
+                ImmutableMetadata.builder().addString("key1", "value1").build();
+        ImmutableMetadata i2 =
+                ImmutableMetadata.builder().addString("key1", "value1").build();
+
+        assertEquals(i1, i2);
+    }
+}