[LANG-1802] Fix collision in CharRange.hashCode()

More tests

Author: garydgregory

src/test/java/org/apache/commons/lang3/CharRangeTest.java

@@ -316,14 +316,42 @@ void testHashCode() {
      */
     @Test
     void testHashCodeLang1802() {
-        // case A：hash=99
-        final CharRange a1 = CharRange.isNotIn((char) 1, (char) 2); // 1,2,true → 83+1+14+1=99
-        final CharRange a2 = CharRange.isIn((char) 2, (char) 2); // 2,2,false → 83+2+14+0=99
-        assertNotEquals(a1.hashCode(), a2.hashCode()); // Collision
-        // case B：hash=123
-        final CharRange b1 = CharRange.isIn((char) 5, (char) 5); // 5,5,false →83+5+35+0=123
-        final CharRange b2 = CharRange.isNotIn((char) 4, (char) 5); // 4,5,true →83+4+35+1=123
-        assertNotEquals(b1.hashCode(), b2.hashCode()); // Collision
+        // Test various combinations of different ranges
+        final CharRange range1 = CharRange.is('a');
+        final CharRange range2 = CharRange.is('b');
+        final CharRange range3 = CharRange.isIn('a', 'z');
+        final CharRange range4 = CharRange.isIn('b', 'z');
+        final CharRange range5 = CharRange.isNot('a');
+        final CharRange range6 = CharRange.isNotIn('a', 'z');
+        final CharRange range7 = CharRange.isNotIn('b', 'z');
+        final CharRange range8 = CharRange.isIn((char) 1, (char) 2);
+        final CharRange range9 = CharRange.isNotIn((char) 1, (char) 2);
+        // Previously problematic cases from LANG-1802 should now have different hash codes
+        final CharRange a1 = CharRange.isNotIn((char) 1, (char) 2);
+        final CharRange a2 = CharRange.isIn((char) 2, (char) 2);
+        assertNotEquals(a1, a2, "Different ranges should not be equal");
+        assertNotEquals(a1.hashCode(), a2.hashCode(), "Different ranges should have different hash codes");
+        final CharRange b1 = CharRange.isIn((char) 5, (char) 5);
+        final CharRange b2 = CharRange.isNotIn((char) 4, (char) 5);
+        assertNotEquals(b1, b2, "Different ranges should not be equal");
+        assertNotEquals(b1.hashCode(), b2.hashCode(), "Different ranges should have different hash codes");
+        // Test that negated and non-negated ranges with same bounds have different hash codes
+        final CharRange normal = CharRange.isIn('x', 'y');
+        final CharRange negated = CharRange.isNotIn('x', 'y');
+        assertNotEquals(normal, negated, "Negated and normal ranges should not be equal");
+        assertNotEquals(normal.hashCode(), negated.hashCode(), "Negated and normal ranges should have different hash codes");
+        // Test that ranges with different start/end produce different hash codes
+        assertNotEquals(range1.hashCode(), range2.hashCode(), "is('a') vs is('b')");
+        assertNotEquals(range1.hashCode(), range3.hashCode(), "is('a') vs isIn('a','z')");
+        assertNotEquals(range3.hashCode(), range4.hashCode(), "isIn('a','z') vs isIn('b','z')");
+        assertNotEquals(range1.hashCode(), range5.hashCode(), "is('a') vs isNot('a')");
+        assertNotEquals(range3.hashCode(), range6.hashCode(), "isIn('a','z') vs isNotIn('a','z')");
+        assertNotEquals(range6.hashCode(), range7.hashCode(), "isNotIn('a','z') vs isNotIn('b','z')");
+        assertNotEquals(range8.hashCode(), range9.hashCode(), "isIn(1,2) vs isNotIn(1,2)");
+        // Test that equal ranges have equal hash codes
+        final CharRange sameAsRange1 = CharRange.is('a');
+        assertEquals(range1, sameAsRange1, "Equal ranges should be equal");
+        assertEquals(range1.hashCode(), sameAsRange1.hashCode(), "Equal ranges should have equal hash codes");
     }
 
     @Test