make Left hashCode implementation different from and Right hashCode

Author: h908714124

build.gradle

@@ -34,8 +34,7 @@ tasks.withType(GenerateModuleMetadata) {
 }
 
 dependencies {
-    testImplementation('org.junit.jupiter:junit-jupiter:5.7.1')
-    testImplementation('com.google.guava:guava-testlib:30.1.1-jre')
+    testImplementation('org.junit.jupiter:junit-jupiter:5.8.2')
 }
 
 jar {

src/main/java/io/jbock/util/Left.java

@@ -1,10 +1,11 @@
 package io.jbock.util;
 
-import java.util.Objects;
 import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
+import static java.util.Objects.requireNonNull;
+
 /**
  * Internal implementation of a Left-Either.
  *
@@ -16,7 +17,7 @@ final class Left<L, R> extends Either<L, R> {
     private final L value;
 
     Left(L value) {
-        this.value = Objects.requireNonNull(value);
+        this.value = requireNonNull(value);
     }
 
     @Override
@@ -112,6 +113,6 @@ public boolean equals(Object obj) {
 
     @Override
     public int hashCode() {
-        return value.hashCode();
+        return 31 * value.hashCode();
     }
 }

src/main/java/io/jbock/util/Right.java

@@ -5,6 +5,8 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 
+import static java.util.Objects.requireNonNull;
+
 /**
  * Internal implementation of a Right-Either.
  *
@@ -16,7 +18,7 @@ final class Right<L, R> extends Either<L, R> {
     private final R value;
 
     Right(R value) {
-        this.value = Objects.requireNonNull(value);
+        this.value = requireNonNull(value);
     }
 
     @Override
@@ -112,6 +114,6 @@ public boolean equals(Object obj) {
 
     @Override
     public int hashCode() {
-        return value.hashCode();
+        return Objects.hash(value);
     }
 }

src/test/java/io/jbock/util/EitherTest.java

@@ -1,6 +1,5 @@
 package io.jbock.util;
 
-import com.google.common.testing.EqualsTester;
 import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
@@ -9,22 +8,31 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 class EitherTest {
 
     @Test
-    void testEquals() {
-        new EqualsTester()
-                .addEqualityGroup(Either.right("1"), Either.right("1"))
-                .addEqualityGroup(Either.right("2"), Either.right("2"))
-                .testEquals();
-        new EqualsTester()
-                .addEqualityGroup(Either.left("1"), Either.left("1"))
-                .addEqualityGroup(Either.left("2"), Either.left("2"))
-                .testEquals();
+    void testEqualsAndHashCode() {
+        assertEquals(Either.right("1"), Either.right("1"));
+        assertEquals(Either.right("1").hashCode(), Either.right("1").hashCode());
+
+        assertNotEquals(Either.right("1"), Either.right("2"));
+        assertNotEquals(Either.right("1").hashCode(), Either.right("2").hashCode());
+        assertNotEquals(Either.<Object, Object>right("1"), Either.right(1));
+
+        assertEquals(Either.left("1"), Either.left("1"));
+        assertEquals(Either.left("1").hashCode(), Either.left("1").hashCode());
+
+        assertNotEquals(Either.left("1"), Either.left("2"));
+        assertNotEquals(Either.left("1").hashCode(), Either.left("2").hashCode());
+        assertNotEquals(Either.<Object, Object>left("1"), Either.left(1));
+
+        assertNotEquals(Either.right("1"), Either.left("1"));
+        assertNotEquals(Either.right("1").hashCode(), Either.left("1").hashCode());
     }
 
     @Test

src/test/java/io/jbock/util/EithersTest.java

@@ -16,11 +16,13 @@ class EithersTest {
     void testOptionalList() {
         assertEquals(Optional.empty(), optionalList(List.of()));
         assertEquals(Optional.of(List.of(1)), optionalList(List.of(1)));
+        assertEquals(Optional.of(List.of(1, 1)), optionalList(List.of(1, 1)));
     }
 
     @Test
     void testToOptionalList() {
         assertEquals(Optional.empty(), Stream.of().collect(toOptionalList()));
         assertEquals(Optional.of(List.of(1)), Stream.of(1).collect(toOptionalList()));
+        assertEquals(Optional.of(List.of(1, 1)), Stream.of(1, 1).collect(toOptionalList()));
     }
 }