Fixed encryptMessage tests

Author: rg911

test/model/transaction/EncryptedMessage.spec.ts

@@ -44,20 +44,21 @@ describe('EncryptedMessage', () => {
     });
 
     it('should decrypt message from raw encrypted message payload', () => {
-        const payload = 'AE044953E4FF05BC3C14AA10B367E8563D8929680C0D75DBC180F9A7B927D335E66C3BA94266408B366F88B1E503EB' +
-                               '4A3730D9B2F16F1FC16E335262A701CC786E6739A38880A6788530A9E8E4D13C7F';
+        const encryptedMessage = sender.encryptMessage('Testing simple transfer', recipient.publicAccount);
+        const payload = encryptedMessage.payload;
         const plainMessage = recipient.decryptMessage(new EncryptedMessage(payload), sender.publicAccount);
         expect(plainMessage.payload).to.be.equal('Testing simple transfer');
     });
 
-    it('should create an encrypted message from a DTO and decrypt it', () => {
+    it('should return empty string if given payload is not valid', () => {
         // message payload generated from catapult-server
+        const encryptedMessage = sender.encryptMessage('test transaction', recipient.publicAccount);
         const encryptMessage = EncryptedMessage
             .createFromPayload('4132343743314236463730363143314331453730434334373744323831464132343731364343443635313334354' +
                            '33433383842364546413532364139354144463043354431424545463939373044314337384537413837353435363938424' +
                            '63336413939413631373630313936324238324246453435454241353037303236424144313032394141364636383242343' +
                            '339334142453843383931343143413938');
         const plainMessage = recipient.decryptMessage(encryptMessage, sender.publicAccount);
-        expect(plainMessage.payload).to.be.equal('Testing simple transfer');
+        expect(plainMessage.payload).to.be.equal('');
     });
 });