Fixed ROT13Converter file name, changed its ID and added tests.

src/app/converter-registry.service.ts

@@ -13,7 +13,7 @@ import {PunycodeDecoder} from './converter/punycode-decoder';
 import {PunycodeEncoder} from './converter/punycode-encoder';
 import {QuotedPrintableDecoder} from './converter/quoted-printable-decoder';
 import {QuotedPrintableEncoder} from './converter/quoted-printable-encoder';
-import {ROT13Converter} from './converter/rot13converter';
+import {ROT13Converter} from './converter/rot13-converter';
 import {URIComponentDecoder} from './converter/uricomponentdecoder';
 import {URIComponentEncoder} from './converter/uricomponentencoder';
 import {URIDecoder} from './converter/uridecoder';

src/app/converter/rot13-converter.spec.ts

@@ -0,0 +1,24 @@
+import {ROT13Converter} from './rot13-converter';
+
+describe('ROT13Converter', () => {
+  let sut: ROT13Converter;
+
+  beforeEach(() => sut = new ROT13Converter());
+
+  it('should create an instance', () => {
+    expect(sut).toBeTruthy();
+  });
+
+  it('should have the id "rot13"', () => {
+    expect(sut.getId()).toEqual('rot13');
+  });
+
+  it('should encode "Hello, World!" to "Uryyb, Jbeyq!"', () => {
+    expect(sut.convert('Hello, World!')).toEqual('Uryyb, Jbeyq!');
+  });
+
+  it('should return the original input after being applied twice', () => {
+    const input = 'Ok, so this string is just a bunch of letters. And numbers: 1, 2, 3. Ans others: /&%. Kthxbye!';
+    expect(sut.convert(sut.convert(input))).toEqual(input);
+  });
+});

src/app/converter/rot13-converter.ts

@@ -6,7 +6,7 @@ export class ROT13Converter implements Converter {
   }
 
   getId(): string {
-    return 'rot13convert';
+    return 'rot13';
   }
 
   convert(input: string): string {