diff --git a/src/test/java/xyz/zhouxy/plusone/commons/util/StrUtilTests.java b/src/test/java/xyz/zhouxy/plusone/commons/util/StrUtilTests.java
index 7ced2dc..7096657 100644
--- a/src/test/java/xyz/zhouxy/plusone/commons/util/StrUtilTests.java
+++ b/src/test/java/xyz/zhouxy/plusone/commons/util/StrUtilTests.java
@@ -11,13 +11,17 @@ class StrUtilTests {
     @Test
     void testFillZero() {
         char c = '=';
+        log.info(StrUtil.fillBefore("123", 6, c));
         log.info(StrUtil.fillBefore("1234", 6, c));
         log.info(StrUtil.fillBefore("12345", 6, c));
         log.info(StrUtil.fillBefore("123456", 6, c));
         log.info(StrUtil.fillBefore("1234567", 6, c));
+        log.info(StrUtil.fillBefore("12345678", 6, c));
+        log.info(StrUtil.fillAfter("123", 6, c));
         log.info(StrUtil.fillAfter("1234", 6, c));
         log.info(StrUtil.fillAfter("12345", 6, c));
         log.info(StrUtil.fillAfter("123456", 6, c));
         log.info(StrUtil.fillAfter("1234567", 6, c));
+        log.info(StrUtil.fillAfter("12345678", 6, c));
     }
 }