[simple-cipher] Fix outdated reference to SimpleCipherStepThreeTest (#2523)

* [simple-cipher] Fix outdated reference to SimpleCipherStepThreeTest

This test file was removed years ago in #1639, but the instructions still mention it (which caused me, at least, quite a bit of confusion since I thought I had deleted something erroneously).

This fixes the documentation to remove the reference to Step Three. If the intent was to never have deleted SimpleCipherStepThreeTest.java in the first place, let me know and I'll amend the PR to that.

* [simple-cipher] Fix incorrect reference to test file in instructions.

This revealed that actually there's a typo in the class name itself.
Determining next whether to fix that or leave it be.

* [simple-cipher] Combine the two test classes into a single suite

* [simple-cipher] Fix checkstyle failures

* [simple-cipher] Remove outdated test files from .meta/config.json

* [simple-cipher] Use Enclosed JUnit runner for inner test classes

Author: apetresc

exercises/practice/simple-cipher/.docs/instructions.append.md

@@ -25,8 +25,7 @@
       "src/main/java/Cipher.java"
     ],
     "test": [
-      "src/test/java/SimpleCipherStepTwoSubsitutionTest.java",
-      "src/test/java/SimpleCipherStepOneTest.java"
+      "src/test/java/SimpleCipherTest.java"
     ],
     "example": [
       ".meta/src/reference/java/Cipher.java"

exercises/practice/simple-cipher/.meta/config.json

@@ -0,0 +1,113 @@
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.experimental.runners.Enclosed;
+import org.junit.runner.RunWith;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+
+@RunWith(Enclosed.class)
+public class SimpleCipherTest {
+    public static class RandomKeyCipher {
+        private Cipher cipherWithDefaultKey;
+
+        @Before
+        public void setup() {
+            cipherWithDefaultKey = new Cipher();
+        }
+
+        /**
+         * Here we take advantage of the fact that plaintext of "aaa..." doesn't output the key. This is a critical
+         * problem with shift ciphers, some characters will always output the key verbatim.
+         */
+        @Test
+        public void cipherCanEncode() {
+            String plainText = "aaaaaaaaaa";
+            String cipherText = cipherWithDefaultKey.getKey().substring(0, 10);
+            assertThat(cipherWithDefaultKey.encode(plainText)).isEqualTo(cipherText);
+        }
+
+        @Ignore("Remove to run test")
+        @Test
+        public void cipherCanDecode() {
+            String cipherText = "aaaaaaaaaa";
+            assertThat(cipherWithDefaultKey.decode(cipherWithDefaultKey.getKey().substring(0, 10)))
+                .isEqualTo(cipherText);
+        }
+
+        @Ignore("Remove to run test")
+        @Test
+        public void cipherIsReversible() {
+            String plainText = "abcdefghij";
+            assertThat(cipherWithDefaultKey.decode(cipherWithDefaultKey.encode(plainText))).isEqualTo(plainText);
+        }
+
+        @Ignore("Remove to run test")
+        @Test
+        public void keyIsLowercaseLetters() {
+            assertThat(cipherWithDefaultKey.getKey()).matches("^[a-z]+$");
+        }
+    }
+
+    public static class SubstitutionCipher {
+        private Cipher cipherWithDefaultKey = new Cipher("abcdefghij");
+
+        @Ignore("Remove to run test")
+        @Test
+        public void cipherCanEncode() {
+            String plainText = "aaaaaaaaaa";
+            String cipherText = "abcdefghij";
+            assertThat(cipherWithDefaultKey.encode(plainText)).isEqualTo(cipherText);
+        }
+
+        @Ignore("Remove to run test")
+        @Test
+        public void cipherCanDecode() {
+            String plainText = "abcdefghij";
+            String cipherText = "aaaaaaaaaa";
+            assertThat(cipherWithDefaultKey.decode(plainText)).isEqualTo(cipherText);
+        }
+
+        @Ignore("Remove to run test")
+        @Test
+        public void cipherIsReversibleGivenKey() {
+            String plainText = "abcdefghij";
+            assertThat(cipherWithDefaultKey.decode(cipherWithDefaultKey.encode(plainText))).isEqualTo(plainText);
+        }
+
+        @Ignore("Remove to run test")
+        @Test
+        public void cipherCanDoubleShiftEncode() {
+            String plainText = "iamapandabear";
+            String cipherText = "qayaeaagaciai";
+            assertThat(new Cipher(plainText).encode(plainText)).isEqualTo(cipherText);
+        }
+
+        @Ignore("Remove to run test")
+        @Test
+        public void cipherCanWrapEncode() {
+            String plainText = "zzzzzzzzzz";
+            String cipherText = "zabcdefghi";
+            assertThat(cipherWithDefaultKey.encode(plainText)).isEqualTo(cipherText);
+        }
+
+        @Ignore("Remove to run test")
+        @Test
+        public void cipherCanWrapDecode() {
+            String plainText = "zabcdefghi";
+            String cipherText = "zzzzzzzzzz";
+            assertThat(cipherWithDefaultKey.decode(plainText)).isEqualTo(cipherText);
+        }
+
+        @Ignore("Remove to run test")
+        @Test
+        public void cipherMessageLongerThanKey() {
+            String plainText = "iamapandabear";
+            String key = "abc";
+            String cipherText = "iboaqcnecbfcr";
+            assertThat(new Cipher(key).encode(plainText)).isEqualTo(cipherText);
+        }
+    }
+}
+