Add draft version of CustomHashCode classes/tests

Author: andrei-punko

src/main/java/by/andd3dfx/common/hashcode/CustomHashCode.java

@@ -0,0 +1,52 @@
+package by.andd3dfx.common.hashcode;
+
+import lombok.Builder;
+import lombok.Data;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.List;
+import java.util.Objects;
+
+@Builder
+@Getter
+@Setter
+public class CustomHashCode {
+
+    private int intPrimitive;
+    private Integer intObject;
+    private String string;
+    private Field customObject;
+    private List<Integer> integersList;
+    private List<Field> objectsList;
+
+    @Data
+    public class Field {
+        private int value;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        CustomHashCode hashCode = (CustomHashCode) o;
+        return intPrimitive == hashCode.intPrimitive
+                && Objects.equals(intObject, hashCode.intObject)
+                && Objects.equals(string, hashCode.string)
+                && Objects.equals(customObject, hashCode.customObject)
+                && Objects.equals(integersList, hashCode.integersList)
+                && Objects.equals(objectsList, hashCode.objectsList);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = intPrimitive;
+        result = 31 * result + (intObject != null ? intObject.hashCode() : 0);
+        result = 31 * result + (string != null ? string.hashCode() : 0);
+        result = 31 * result + (customObject != null ? customObject.hashCode() : 0);
+        result = 31 * result + (integersList != null ? integersList.hashCode() : 0);
+        result = 31 * result + (objectsList != null ? objectsList.hashCode() : 0);
+        return result;
+    }
+}

src/main/java/by/andd3dfx/common/hashcode/CustomHashCode2.java

@@ -0,0 +1,46 @@
+package by.andd3dfx.common.hashcode;
+
+import lombok.Builder;
+import lombok.Data;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.List;
+import java.util.Objects;
+
+@Builder
+@Getter
+@Setter
+public class CustomHashCode2 {
+
+    private int intPrimitive;
+    private Integer intObject;
+    private String string;
+    private Field customObject;
+    private List<Integer> integersList;
+    private List<Field> objectsList;
+
+    @Data
+    public class Field {
+        private int value;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        CustomHashCode2 hashCode2 = (CustomHashCode2) o;
+        return intPrimitive == hashCode2.intPrimitive
+                && Objects.equals(intObject, hashCode2.intObject)
+                && Objects.equals(string, hashCode2.string)
+                && Objects.equals(customObject, hashCode2.customObject)
+                && Objects.equals(integersList, hashCode2.integersList)
+                && Objects.equals(objectsList, hashCode2.objectsList);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(intPrimitive, intObject, string, customObject, integersList, objectsList);
+    }
+}

src/test/java/by/andd3dfx/common/hashcode/CustomHashCode2Test.java

@@ -0,0 +1,50 @@
+package by.andd3dfx.common.hashcode;
+
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class CustomHashCode2Test {
+
+    private final CustomHashCode2 OBJ1 = CustomHashCode2.builder()
+            .intPrimitive(12)
+            .integersList(List.of(1, 2))
+            .build();
+    private final CustomHashCode2 OBJ2 = CustomHashCode2.builder()
+            .intPrimitive(13)
+            .integersList(List.of(2, 3))
+            .build();
+    private final CustomHashCode2 OBJ3 = CustomHashCode2.builder()
+            .intPrimitive(12)
+            .integersList(List.of(1, 2))
+            .build();
+    
+    @Test
+    public void testHashCode() {
+        assertThat(OBJ1.hashCode()).isNotEqualTo(OBJ2.hashCode());
+        assertThat(OBJ1.hashCode()).isEqualTo(OBJ3.hashCode());
+    }
+
+    @Test
+    public void testEquals() {
+        // Object equals to itself
+        assertThat(OBJ1.equals(OBJ1)).isTrue();
+        assertThat(OBJ2.equals(OBJ2)).isTrue();
+        assertThat(OBJ3.equals(OBJ3)).isTrue();
+
+        // Different objects, different classes
+        assertThat(OBJ1.equals("OBJ1")).isFalse();
+        assertThat(OBJ2.equals("OBJ2")).isFalse();
+        assertThat(OBJ3.equals("OBJ3")).isFalse();
+
+        // Different objects, same class
+        assertThat(OBJ1.equals(OBJ2)).isFalse();
+        assertThat(OBJ2.equals(OBJ1)).isFalse();
+
+        // Equal objects
+        assertThat(OBJ1.equals(OBJ3)).isTrue();
+        assertThat(OBJ3.equals(OBJ1)).isTrue();
+    }
+}

src/test/java/by/andd3dfx/common/hashcode/CustomHashCodeTest.java

@@ -0,0 +1,50 @@
+package by.andd3dfx.common.hashcode;
+
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class CustomHashCodeTest {
+
+    private final CustomHashCode OBJ1 = CustomHashCode.builder()
+            .intPrimitive(12)
+            .integersList(List.of(1, 2))
+            .build();
+    private final CustomHashCode OBJ2 = CustomHashCode.builder()
+            .intPrimitive(13)
+            .integersList(List.of(2, 3))
+            .build();
+    private final CustomHashCode OBJ3 = CustomHashCode.builder()
+            .intPrimitive(12)
+            .integersList(List.of(1, 2))
+            .build();
+    
+    @Test
+    public void testHashCode() {
+        assertThat(OBJ1.hashCode()).isNotEqualTo(OBJ2.hashCode());
+        assertThat(OBJ1.hashCode()).isEqualTo(OBJ3.hashCode());
+    }
+
+    @Test
+    public void testEquals() {
+        // Object equals to itself
+        assertThat(OBJ1.equals(OBJ1)).isTrue();
+        assertThat(OBJ2.equals(OBJ2)).isTrue();
+        assertThat(OBJ3.equals(OBJ3)).isTrue();
+
+        // Different objects, different classes
+        assertThat(OBJ1.equals("OBJ1")).isFalse();
+        assertThat(OBJ2.equals("OBJ2")).isFalse();
+        assertThat(OBJ3.equals("OBJ3")).isFalse();
+
+        // Different objects, same class
+        assertThat(OBJ1.equals(OBJ2)).isFalse();
+        assertThat(OBJ2.equals(OBJ1)).isFalse();
+
+        // Equal objects
+        assertThat(OBJ1.equals(OBJ3)).isTrue();
+        assertThat(OBJ3.equals(OBJ1)).isTrue();
+    }
+}