Fixed DecToHexConverter filename, added test and fixed other tests.

src/app/converter-registry.service.ts

@@ -3,7 +3,7 @@ import {Base64Encoder} from './converter/base64-encoder';
 import {BinToDecConverter} from './converter/bin-to-dec-converter';
 import {Converter} from './converter/converter';
 import {DecToBinConverter} from './converter/dec-to-bin-converter';
-import {DecToHexConverter} from './converter/dectohexconverter';
+import {DecToHexConverter} from './converter/dec-to-hex-converter';
 import {HexToDecConverter} from './converter/hextodecconverter';
 import {HTMLEntitiesDecoder} from './converter/htmlentitiesdecoder';
 import {HTMLEntitiesEncoder} from './converter/htmlentitiesencoder';

src/app/converter/bin-to-dec-converter.spec.ts

@@ -4,7 +4,7 @@ describe('BinToDecConverter', () => {
   it('should create an instance', () => {
     expect(new BinToDecConverter()).toBeTruthy();
   });
-  it('should have the id "base64encode"', () => {
+  it('should have the id "bintodec"', () => {
     expect(new BinToDecConverter().getId()).toEqual('bintodec');
   });
   it('should convert "11011" to "27"', () => {

src/app/converter/dec-to-bin-converter.spec.ts

@@ -4,7 +4,7 @@ describe('DecToBinConverter', () => {
   it('should create an instance', () => {
     expect(new DecToBinConverter()).toBeTruthy();
   });
-  it('should have the id "base64encode"', () => {
+  it('should have the id "dectobin"', () => {
     expect(new DecToBinConverter().getId()).toEqual('dectobin');
   });
   it('should convert "22" to "10110"', () => {

src/app/converter/dec-to-hex-converter.spec.ts

@@ -0,0 +1,16 @@
+import {DecToHexConverter} from './dec-to-hex-converter';
+
+describe('DecToHexConverter', () => {
+  it('should create an instance', () => {
+    expect(new DecToHexConverter()).toBeTruthy();
+  });
+  it('should have the id "dectohex"', () => {
+    expect(new DecToHexConverter().getId()).toEqual('dectohex');
+  });
+  it('should convert "22" to "16"', () => {
+    expect(new DecToHexConverter().convert('22')).toEqual('16');
+  });
+  it('should raise an exception on invalid input', () => {
+    expect(() => new DecToHexConverter().convert('foo bar')).toThrowError('The input seems not to be a valid integer.');
+  });
+});