atbash-cipher: Replace [<TestCase>] tests with individual tests (#298)

exercises/atbash-cipher/AtbashTest.fs

@@ -3,12 +3,50 @@ module AtbashTest
 open NUnit.Framework
 open Atbash
 
-[<TestCase("no", ExpectedResult = "ml")>]
-[<TestCase("yes", ExpectedResult = "bvh", Ignore = "Remove to run test case")>]
-[<TestCase("OMG", ExpectedResult = "lnt", Ignore = "Remove to run test case")>]
-[<TestCase("mindblowingly", ExpectedResult = "nrmwy oldrm tob", Ignore = "Remove to run test case")>]
-[<TestCase("Testing, 1 2 3, testing.", ExpectedResult = "gvhgr mt123 gvhgr mt", Ignore = "Remove to run test case")>]
-[<TestCase("Truth is fiction.", ExpectedResult = "gifgs rhurx grlm", Ignore = "Remove to run test case")>]
-[<TestCase("The quick brown fox jumps over the lazy dog.", ExpectedResult = "gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt", Ignore = "Remove to run test case")>]
-let ``Encodes words using atbash cipher`` words =        
-    encode words
+let ``Encode yes`` () =
+    let phrase = "yes"
+    let expected = "bvh"
+    let actual = encode phrase
+    Assert.That(actual, Is.EqualTo(expected))
+
+let ``Encode no`` () =
+    let phrase = "no"
+    let expected = "ml"
+    let actual = encode phrase
+    Assert.That(actual, Is.EqualTo(expected))
+
+let ``Encode OMG`` () =
+    let phrase = "OMG"
+    let expected = "lnt"
+    let actual = encode phrase
+    Assert.That(actual, Is.EqualTo(expected))
+
+let ``Encode spaces`` () =
+    let phrase = "O M G"
+    let expected = "lnt"
+    let actual = encode phrase
+    Assert.That(actual, Is.EqualTo(expected))
+
+let ``Encode mindblowingly`` () =
+    let phrase = "mindblowingly"
+    let expected = "nrmwy oldrm tob"
+    let actual = encode phrase
+    Assert.That(actual, Is.EqualTo(expected))
+
+let ``Encode numbers`` () =
+    let phrase = "Testing, 1 2 3, testing."
+    let expected = "gvhgr mt123 gvhgr mt"
+    let actual = encode phrase
+    Assert.That(actual, Is.EqualTo(expected))
+
+let ``Encode deep thought`` () =
+    let phrase = "Truth is fiction."
+    let expected = "gifgs rhurx grlm"
+    let actual = encode phrase
+    Assert.That(actual, Is.EqualTo(expected))
+
+let ``Encode all the letters`` () =
+    let phrase = "The quick brown fox jumps over the lazy dog."
+    let expected = "gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt"
+    let actual = encode phrase
+    Assert.That(actual, Is.EqualTo(expected))