modify and expand snowflake link_id_regex tests

Author: Ian-Nara

src/test/java/com/uid2/admin/vertx/ServiceLinkServiceTest.java

@@ -624,9 +624,15 @@ private static java.util.stream.Stream<org.junit.jupiter.params.provider.Argumen
         return java.util.stream.Stream.of(
                 org.junit.jupiter.params.provider.Arguments.of("link[0-9]+", "invalidLink", false),
                 org.junit.jupiter.params.provider.Arguments.of("link[0-9]+", "link42", true),
-                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9]{6,20}$", "XY12345", true), // snowflake valid
-                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9]{6,20}$", "UID2ENVIRONMENT", true), // snowflake valid
-                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9]{6,20}$", "xy12345", false) // snowflake invalid
+                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9_]{1,256}$", "XY12345", true), // snowflake valid
+                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9_]{1,256}$", "UID2_ENVIRONMENT", true), // snowflake valid
+                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9_]{1,256}$", "xy12345", false), // snowflake invalid
+                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9_]{1,256}$", "X", true), // snowflake valid, minimum length
+                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9_]{1,256}$", "X".repeat(256), true), // snowflake valid, maximum length
+                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9_]{1,256}$", "X".repeat(257), false), // snowflake invalid, exceeds maximum length
+                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9_]{1,256}$", " XY12345", false), // snowflake invalid, leading whitespace
+                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9_]{1,256}$", "XY12345 ", false), // snowflake invalid, trailing whitespace
+                org.junit.jupiter.params.provider.Arguments.of("^[A-Z0-9_]{1,256}$", "XY 12345", false) // snowflake invalid, whitespace in the middle
         );
     }
 }