add test

hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java

@@ -225,4 +225,22 @@ public class CharSequenceUtilTest {
 		Assert.assertEquals(CharSequenceUtil.repeat(CharSequenceUtil.SPACE, 10), CharSequenceUtil.commonSuffix(str1, str2));
 	}
 
+	@Test
+	public void testContainsOnly() {
+		// 测试空字符串
+		Assert.assertTrue(CharSequenceUtil.containsOnly("", 'a', 'b'));
+
+		// 测试字符串只包含testChars中的字符
+		Assert.assertTrue(CharSequenceUtil.containsOnly("asdf", 'a', 's', 'd', 'f'));
+
+		// 测试字符串包含testChars中的字符和其它字符
+		Assert.assertFalse(CharSequenceUtil.containsOnly("asdf123", 'a', 's', 'd', 'f'));
+
+		// 测试字符串不包含testChars中的任何字符
+		Assert.assertFalse(CharSequenceUtil.containsOnly("hello", 'a', 'b'));
+
+		// 测试字符串为null
+		Assert.assertTrue(CharSequenceUtil.containsOnly(null, 'a', 'b'));
+	}
+
 }