handle non-finite bounds in BigIntegerValidator range checks

src/main/java/org/apache/commons/validator/routines/BigIntegerValidator.java

@@ -152,7 +152,8 @@ public boolean maxValue(final BigInteger value, final long max) {
      * <p>
      * This overrides the {@link Number} overload inherited from the superclass, which narrows the value to a {@code long} before comparing and so loses
      * magnitude for a {@code BigInteger} outside the long range. The operands are compared as {@code BigDecimal} so a non-integer bound keeps its fractional
-     * part instead of being truncated towards zero.
+     * part instead of being truncated towards zero. A non-finite {@link Double} or {@link Float} operand keeps the {@code doubleValue()} comparison, since
+     * {@code BigDecimal} cannot represent {@code NaN} or an infinity.
      * </p>
      *
      * @param value The value validation is being performed on.
@@ -161,7 +162,7 @@ public boolean maxValue(final BigInteger value, final long max) {
      */
     @Override
     public boolean maxValue(final Number value, final Number max) {
-        return toBigDecimal(value).compareTo(toBigDecimal(max)) <= 0;
+        return isFinite(value) && isFinite(max) ? compareTo(value, max) <= 0 : value.doubleValue() <= max.doubleValue();
     }
 
     /**
@@ -181,7 +182,8 @@ public boolean minValue(final BigInteger value, final long min) {
      * <p>
      * This overrides the {@link Number} overload inherited from the superclass, which narrows the value to a {@code long} before comparing and so loses
      * magnitude for a {@code BigInteger} outside the long range. The operands are compared as {@code BigDecimal} so a non-integer bound keeps its fractional
-     * part instead of being truncated towards zero.
+     * part instead of being truncated towards zero. A non-finite {@link Double} or {@link Float} operand keeps the {@code doubleValue()} comparison, since
+     * {@code BigDecimal} cannot represent {@code NaN} or an infinity.
      * </p>
      *
      * @param value The value validation is being performed on.
@@ -190,7 +192,7 @@ public boolean minValue(final BigInteger value, final long min) {
      */
     @Override
     public boolean minValue(final Number value, final Number min) {
-        return toBigDecimal(value).compareTo(toBigDecimal(min)) >= 0;
+        return isFinite(value) && isFinite(min) ? compareTo(value, min) >= 0 : value.doubleValue() >= min.doubleValue();
     }
 
     /**

src/test/java/org/apache/commons/validator/routines/BigIntegerValidatorTest.java

@@ -238,4 +238,30 @@ void testNumberRangeOutsideLongRange() {
         assertEquals(50L, wrapsIntoRange.longValue());
         assertFalse(instance.isInRange(wrapsIntoRange, min, max));
     }
+
+    /**
+     * A non-finite {@link Double} bound must not be routed through {@link BigDecimal}, which cannot represent {@code NaN} or an infinity. The {@link Number}
+     * overloads previously converted every bound to a {@code BigDecimal} and so threw {@code NumberFormatException} for such a bound, whereas the sibling
+     * {@link BigDecimalValidator} already handled it. The behaviour now matches: a {@code NaN} bound is never satisfied, and an infinity is an open bound.
+     */
+    @Test
+    void testNumberRangeNonFiniteBound() {
+        final AbstractNumberValidator instance = BigIntegerValidator.getInstance();
+        final Number value = BigInteger.valueOf(100);
+
+        // NaN bound: nothing compares against NaN
+        assertFalse(instance.maxValue(value, Double.NaN));
+        assertFalse(instance.minValue(value, Double.NaN));
+        assertFalse(instance.isInRange(value, 0, Double.NaN));
+        assertFalse(instance.isInRange(value, Double.NaN, 200));
+
+        // POSITIVE_INFINITY as a maximum / NEGATIVE_INFINITY as a minimum are open bounds any finite value meets
+        assertTrue(instance.maxValue(value, Double.POSITIVE_INFINITY));
+        assertTrue(instance.minValue(value, Double.NEGATIVE_INFINITY));
+        assertTrue(instance.isInRange(value, Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY));
+
+        // POSITIVE_INFINITY as a minimum / NEGATIVE_INFINITY as a maximum cannot be met
+        assertFalse(instance.minValue(value, Double.POSITIVE_INFINITY));
+        assertFalse(instance.maxValue(value, Double.NEGATIVE_INFINITY));
+    }
 }