From ce638de9b1c500ea53589133c1aebb2ad802e965 Mon Sep 17 00:00:00 2001
From: Flavio Diez <flavio.diez@metronom-external.com>
Date: Mon, 27 Jan 2020 14:43:00 +0100
Subject: [PATCH] Corrected padding and added error cases

---
 src/core/operations/RailFenceCypherDecode.mjs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/core/operations/RailFenceCypherDecode.mjs b/src/core/operations/RailFenceCypherDecode.mjs
index 1c9c67b5..20a8a4f2 100644
--- a/src/core/operations/RailFenceCypherDecode.mjs
+++ b/src/core/operations/RailFenceCypherDecode.mjs
@@ -48,10 +48,16 @@ class RailFenceCypherDecode extends Operation {
 
         let cipher = input;
 
+        if (key < 2) {
+            return "Key has to be bigger than 2";
+        } else if (key > cipher.length) {
+            return "Key should be smaller than the cipher's length";
+        }
+
         const rest = cipher.length % key;
 
         if (rest !== 0) {
-            cipher = cipher + (" ".repeat(rest));
+            cipher = cipher + (" ".repeat(key-rest));
         }
 
         const blockLen = cipher.length / key;