Atbash - use object instead of an instance - refs exercism#242. Add A…

…tbash.scala - refs exercism#137. Add topics to config.json - refs exercism#125

config.json

@@ -179,6 +179,9 @@
       "slug": "atbash-cipher",
       "difficulty": 1,
       "topics": [
+         "Strings",
+         "Transforming",
+         "Security"
       ]
 		},
     {

exercises/atbash-cipher/example.scala

@@ -1,9 +1,9 @@
-case class Atbash() {
-  def encode(s: String): String =
-    s.foldLeft("")((acc, c) => acc + substitute(c)).grouped(5).mkString(" ")
-
+object Atbash {
   private def substitute(c: Char) =
     if (c.isDigit) c.toString
     else if (c.isLetter) ('a' + ('z' - c.toLower)).toChar.toString
     else ""
+
+  def encode(s: String): String =
+    s.foldLeft("")((acc, c) => acc + substitute(c)).grouped(5).mkString(" ")
 }

exercises/atbash-cipher/src/main/scala/Atbash.scala

@@ -0,0 +1,3 @@
+object Atbash {
+  def encode(s: String): String = ???
+}

exercises/atbash-cipher/src/test/scala/atbash_test.scala

@@ -2,47 +2,47 @@ import org.scalatest.{Matchers, FlatSpec}
 
 class AtbashTest extends FlatSpec with Matchers {
   it should "encode no" in {
-    Atbash().encode("no") should equal("ml")
+    Atbash.encode("no") should equal("ml")
   }
 
   it should "encode yes" in {
     pending
-    Atbash().encode("yes") should equal("bvh")
+    Atbash.encode("yes") should equal("bvh")
   }
 
   it should "encode OMG" in {
     pending
-    Atbash().encode("OMG") should equal("lnt")
+    Atbash.encode("OMG") should equal("lnt")
   }
 
   it should "encode lowercase omg" in {
     pending
-    Atbash().encode("omg") should equal("lnt")
+    Atbash.encode("omg") should equal("lnt")
   }
 
   it should "encode O M G" in {
     pending
-    Atbash().encode("O M G ") should equal("lnt")
+    Atbash.encode("O M G ") should equal("lnt")
   }
 
   it should "encode and group string " in {
     pending
-    Atbash().encode("mindblowingly") should equal("nrmwy oldrm tob")
+    Atbash.encode("mindblowingly") should equal("nrmwy oldrm tob")
   }
 
   it should "encode string with digits and punctuation" in {
     pending
-    Atbash().encode("Testing, 1 2 3, testing. ") should equal("gvhgr mt123 gvhgr mt")
+    Atbash.encode("Testing, 1 2 3, testing. ") should equal("gvhgr mt123 gvhgr mt")
   }
 
   it should "encode \"Truth is fiction.\"" in {
     pending
-    Atbash().encode("Truth is fiction.") should equal("gifgs rhurx grlm")
+    Atbash.encode("Truth is fiction.") should equal("gifgs rhurx grlm")
   }
 
   it should "encode a long string" in {
     pending
-    Atbash().encode("The quick brown fox jumps over the lazy dog.") should
+    Atbash.encode("The quick brown fox jumps over the lazy dog.") should
       equal("gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt")
   }
 }