JAV-38 Inner transaction singer delegation

src/model/transaction/AggregateTransaction.ts

@@ -289,12 +289,19 @@ export class AggregateTransaction extends Transaction {
      * @internal
      * @returns {Uint8Array}
      */
-    protected generateBytes(): Uint8Array {
+    protected generateBytes(signer?: PublicAccount): Uint8Array {
         const signerBuffer = new Uint8Array(32);
         const signatureBuffer = new Uint8Array(64);
-
         let transactions = Uint8Array.from([]);
         this.innerTransactions.forEach((transaction) => {
+            if (!transaction.signer) {
+                if (this.type === TransactionType.AGGREGATE_COMPLETE) {
+                    transaction = Object.assign({__proto__: Object.getPrototypeOf(transaction)}, transaction, {signer});
+                } else {
+                    throw new Error(
+                        'InnerTransaction signer must be provide. Only AggregateComplete transaction can use delegated signer.');
+                }
+            }
             const transactionByte = transaction.toAggregateTransactionBytes();
             transactions = GeneratorUtils.concatTypedArrays(transactions, transactionByte);
         });

src/model/transaction/InnerTransaction.ts

@@ -20,4 +20,4 @@ import {Transaction} from './Transaction';
 /**
  * Transaction with signer included, used when adding signer to transactions included in an aggregate transaction.
  */
-export type InnerTransaction = Transaction &  {signer: PublicAccount};
+export type InnerTransaction = Transaction &  {signer?: PublicAccount};

src/model/transaction/Transaction.ts

@@ -105,8 +105,9 @@ export abstract class Transaction {
 
     /**
      * @internal
+     * @param singer Optional singer for delegated aggregate complete transaction only.
      */
-    protected abstract generateBytes(): Uint8Array;
+    protected abstract generateBytes(signer?: PublicAccount): Uint8Array;
 
     /**
      * @internal
@@ -123,7 +124,7 @@ export abstract class Transaction {
     public signWith(account: Account, generationHash: string): SignedTransaction {
         const generationHashBytes = Array.from(Convert.hexToUint8(generationHash));
         const signSchema = SHA3Hasher.resolveSignSchema(account.networkType);
-        const byteBuffer = Array.from(this.generateBytes());
+        const byteBuffer = Array.from(this.generateBytes(account.publicAccount));
         const signingBytes = generationHashBytes.concat(byteBuffer.slice(4 + 64 + 32));
         const keyPairEncoded = KeyPair.createKeyPairFromPrivateKeyString(account.privateKey, signSchema);
         const signature = Array.from(KeyPair.sign(account, new Uint8Array(signingBytes), signSchema));
@@ -162,10 +163,12 @@ export abstract class Transaction {
 
     /**
      * Convert an aggregate transaction to an inner transaction including transaction signer.
-     * @param signer - Transaction signer.
+     * Signer is optional for `AggregateComplete` transaction `ONLY`.
+     * If no signer provided, aggregate transaction signer will be delegated on signing
+     * @param signer - Innre transaction signer. (Optional for `AggregateComplete` transaction `ONLY`)
      * @returns InnerTransaction
      */
-    public toAggregate(signer: PublicAccount): InnerTransaction {
+    public toAggregate(signer?: PublicAccount): InnerTransaction {
         if (this.type === TransactionType.AGGREGATE_BONDED || this.type === TransactionType.AGGREGATE_COMPLETE) {
             throw new Error('Inner transaction cannot be an aggregated transaction.');
         }

src/service/AggregateTransactionService.ts

@@ -53,7 +53,7 @@ export class AggregateTransactionService {
             signers.push(signedTransaction.signerPublicKey);
         }
         return observableFrom(aggregateTransaction.innerTransactions).pipe(
-            mergeMap((innerTransaction) => this.accountHttp.getMultisigAccountInfo(innerTransaction.signer.address)
+            mergeMap((innerTransaction) => this.accountHttp.getMultisigAccountInfo(innerTransaction.signer!.address)
                 .pipe(
                     /**
                      * For multisig account, we need to get the graph info in case it has multiple levels

test/model/transaction/AggregateTransaction.spec.ts

@@ -18,6 +18,7 @@ import {expect} from 'chai';
 import {ChronoUnit} from 'js-joda';
 import { TransactionMapping } from '../../../src/core/utils/TransactionMapping';
 import {CreateTransactionFromDTO} from '../../../src/infrastructure/transaction/CreateTransactionFromDTO';
+import { CreateTransactionFromPayload } from '../../../src/infrastructure/transaction/CreateTransactionFromPayload';
 import {Account} from '../../../src/model/account/Account';
 import {Address} from '../../../src/model/account/Address';
 import {PublicAccount} from '../../../src/model/account/PublicAccount';
@@ -116,6 +117,55 @@ describe('AggregateTransaction', () => {
         )).to.be.equal('019054419050B9837EFAB4BBE8A4B9BB32D812F9885C00D8FC1650E1420D000000746573742D6D657373616765');
     });
 
+    it('should createComplete an AggregateTransaction object with delegated signer', () => {
+        const transferTransaction = TransferTransaction.create(
+            Deadline.create(1, ChronoUnit.HOURS),
+            Address.createFromRawAddress('SBILTA367K2LX2FEXG5TFWAS7GEFYAGY7QLFBYKC'),
+            [],
+            PlainMessage.create('test-message'),
+            NetworkType.MIJIN_TEST,
+        );
+
+        const aggregateTransaction = AggregateTransaction.createComplete(
+            Deadline.create(),
+            [transferTransaction.toAggregate()],
+            NetworkType.MIJIN_TEST,
+            []);
+        expect(aggregateTransaction.innerTransactions[0].signer).to.be.undefined;
+
+        const signedTransaction = aggregateTransaction.signWith(account, generationHash);
+
+        expect(signedTransaction.payload.substring(0, 8)).to.be.equal('CD000000');
+        expect(signedTransaction.payload.substring(240, 256)).to.be.equal('5100000051000000');
+        expect(signedTransaction.payload.substring(
+            320,
+            signedTransaction.payload.length,
+        )).to.be.equal('019054419050B9837EFAB4BBE8A4B9BB32D812F9885C00D8FC1650E1420D000000746573742D6D657373616765');
+
+        const createdFromPayload = CreateTransactionFromPayload(signedTransaction.payload);
+        expect((createdFromPayload as AggregateTransaction).innerTransactions[0].signer!.publicKey)
+            .to.be.equal(account.publicKey);
+    });
+
+    it('should throw exception with delegated signer', () => {
+        expect(() => {
+            const transferTransaction = TransferTransaction.create(
+                Deadline.create(1, ChronoUnit.HOURS),
+                Address.createFromRawAddress('SBILTA367K2LX2FEXG5TFWAS7GEFYAGY7QLFBYKC'),
+                [],
+                PlainMessage.create('test-message'),
+                NetworkType.MIJIN_TEST,
+            );
+            const aggregateTransaction = AggregateTransaction.createBonded(
+                Deadline.create(),
+                [transferTransaction.toAggregate()],
+                NetworkType.MIJIN_TEST,
+                []);
+
+            aggregateTransaction.signWith(account, generationHash);
+        }).to.throw(Error, 'InnerTransaction signer must be provide. Only AggregateComplete transaction can use delegated signer.');
+    });
+
     it('should createComplete an AggregateTransaction object with NamespaceRegistrationTransaction', () => {
         const registerNamespaceTransaction = NamespaceRegistrationTransaction.createRootNamespace(
             Deadline.create(),