Test hashCode is equal when the fractions are equal.
This test currently fails and is marked disabled.
diff --git a/commons-numbers-fraction/src/test/java/org/apache/commons/numbers/fraction/BigFractionTest.java b/commons-numbers-fraction/src/test/java/org/apache/commons/numbers/fraction/BigFractionTest.java
index 8bbcc14..a24a801 100644
--- a/commons-numbers-fraction/src/test/java/org/apache/commons/numbers/fraction/BigFractionTest.java
+++ b/commons-numbers-fraction/src/test/java/org/apache/commons/numbers/fraction/BigFractionTest.java
@@ -22,6 +22,7 @@
import org.apache.commons.numbers.core.TestUtils;
import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Disabled;
import org.junit.jupiter.api.Test;
@@ -591,28 +592,38 @@
Assertions.assertEquals(new BigDecimal("0.333"), BigFraction.of(1, 3).bigDecimalValue(3, RoundingMode.DOWN));
}
+ @Disabled
@Test
public void testEqualsAndHashCode() {
BigFraction zero = BigFraction.of(0, 1);
- BigFraction nullFraction = null;
Assertions.assertEquals(zero, zero);
- Assertions.assertFalse(zero.equals(nullFraction));
+ Assertions.assertFalse(zero.equals(null));
+ Assertions.assertFalse(zero.equals(new Object()));
Assertions.assertFalse(zero.equals(Double.valueOf(0)));
+
+ // Equal to same rational number
BigFraction zero2 = BigFraction.of(0, 2);
- Assertions.assertEquals(zero, zero2);
- Assertions.assertEquals(zero.hashCode(), zero2.hashCode());
+ assertEqualAndHashCodeEqual(zero, zero2);
+
+ // Not equal to different rational number
BigFraction one = BigFraction.of(1, 1);
Assertions.assertNotEquals(zero, one);
Assertions.assertNotEquals(one, zero);
- Assertions.assertEquals(BigFraction.ONE, one);
- BigFraction one2 = BigFraction.of(-1, -1);
- Assertions.assertEquals(one2, one);
- Assertions.assertEquals(one, one2);
- BigFraction minusOne = BigFraction.of(-1, 1);
- BigFraction minusOne2 = BigFraction.of(1, -1);
- Assertions.assertEquals(minusOne2, minusOne);
- Assertions.assertEquals(minusOne, minusOne2);
+ // Test using different representations of the same fraction
+ // (Denominators are primes)
+ for (int[] f : new int[][] {{1, 1}, {2, 3}, {6826, 15373}, {1373, 103813}}) {
+ final int num = f[0];
+ final int den = f[1];
+ BigFraction f1 = BigFraction.of(-num, den);
+ BigFraction f2 = BigFraction.of(num, -den);
+ assertEqualAndHashCodeEqual(f1, f2);
+ assertEqualAndHashCodeEqual(f2, f1);
+ f1 = BigFraction.of(num, den);
+ f2 = BigFraction.of(-num, -den);
+ assertEqualAndHashCodeEqual(f1, f2);
+ assertEqualAndHashCodeEqual(f2, f1);
+ }
// Same numerator or denominator as 1/1
BigFraction half = BigFraction.of(1, 2);
@@ -621,6 +632,22 @@
Assertions.assertNotEquals(one, two);
}
+ /**
+ * Assert the two fractions are equal. The contract of {@link Object#hashCode()} requires
+ * that the hash code must also be equal.
+ *
+ * <p>This method must not be called with the same instance for both arguments. It is
+ * intended to be used to test different objects that are equal have the same hash code.
+ *
+ * @param f1 Fraction 1.
+ * @param f2 Fraction 2.
+ */
+ private static void assertEqualAndHashCodeEqual(BigFraction f1, BigFraction f2) {
+ Assertions.assertNotSame(f1, f2, "Do not call this assertion with the same object");
+ Assertions.assertEquals(f1, f2);
+ Assertions.assertEquals(f1.hashCode(), f2.hashCode(), "Equal fractions have different hashCode");
+ }
+
@Test
public void testPow() {
Assertions.assertEquals(BigFraction.of(8192, 1594323), BigFraction.of(2, 3).pow(13));
diff --git a/commons-numbers-fraction/src/test/java/org/apache/commons/numbers/fraction/FractionTest.java b/commons-numbers-fraction/src/test/java/org/apache/commons/numbers/fraction/FractionTest.java
index 5534d2e..cf6e747 100644
--- a/commons-numbers-fraction/src/test/java/org/apache/commons/numbers/fraction/FractionTest.java
+++ b/commons-numbers-fraction/src/test/java/org/apache/commons/numbers/fraction/FractionTest.java
@@ -19,6 +19,7 @@
import org.apache.commons.numbers.core.TestUtils;
import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Disabled;
import org.junit.jupiter.api.Test;
@@ -422,27 +423,38 @@
);
}
+ @Disabled
@Test
public void testEqualsAndHashCode() {
Fraction zero = Fraction.of(0, 1);
- Fraction nullFraction = null;
Assertions.assertEquals(zero, zero);
- Assertions.assertNotEquals(zero, nullFraction);
+ Assertions.assertNotEquals(zero, null);
+ Assertions.assertFalse(zero.equals(new Object()));
Assertions.assertFalse(zero.equals(Double.valueOf(0)));
+
+ // Equal to same rational number
Fraction zero2 = Fraction.of(0, 2);
- Assertions.assertEquals(zero, zero2);
- Assertions.assertEquals(zero.hashCode(), zero2.hashCode());
+ assertEqualAndHashCodeEqual(zero, zero2);
+
+ // Not equal to different rational number
Fraction one = Fraction.of(1, 1);
Assertions.assertNotEquals(zero, one);
Assertions.assertNotEquals(one, zero);
- Fraction one2 = Fraction.of(-1, -1);
- Assertions.assertEquals(one2, one);
- Assertions.assertEquals(one, one2);
- Fraction minusOne = Fraction.of(-1, 1);
- Fraction minusOne2 = Fraction.of(1, -1);
- Assertions.assertEquals(minusOne2, minusOne);
- Assertions.assertEquals(minusOne, minusOne2);
+ // Test using different representations of the same fraction
+ // (Denominators are primes)
+ for (int[] f : new int[][] {{1, 1}, {2, 3}, {6826, 15373}, {1373, 103813}}) {
+ final int num = f[0];
+ final int den = f[1];
+ Fraction f1 = Fraction.of(-num, den);
+ Fraction f2 = Fraction.of(num, -den);
+ assertEqualAndHashCodeEqual(f1, f2);
+ assertEqualAndHashCodeEqual(f2, f1);
+ f1 = Fraction.of(num, den);
+ f2 = Fraction.of(-num, -den);
+ assertEqualAndHashCodeEqual(f1, f2);
+ assertEqualAndHashCodeEqual(f2, f1);
+ }
// Same numerator or denominator as 1/1
Fraction half = Fraction.of(1, 2);
@@ -462,6 +474,22 @@
Assertions.assertNotEquals(almostZero, almostZero2);
}
+ /**
+ * Assert the two fractions are equal. The contract of {@link Object#hashCode()} requires
+ * that the hash code must also be equal.
+ *
+ * <p>This method must not be called with the same instance for both arguments. It is
+ * intended to be used to test different objects that are equal have the same hash code.
+ *
+ * @param f1 Fraction 1.
+ * @param f2 Fraction 2.
+ */
+ private static void assertEqualAndHashCodeEqual(Fraction f1, Fraction f2) {
+ Assertions.assertNotSame(f1, f2, "Do not call this assertion with the same object");
+ Assertions.assertEquals(f1, f2);
+ Assertions.assertEquals(f1.hashCode(), f2.hashCode(), "Equal fractions have different hashCode");
+ }
+
@Test
public void testAdditiveNeutral() {
Assertions.assertEquals(Fraction.ZERO, Fraction.ONE.zero());
