txnbuild: add AddSignatureDecorated

txnbuild/CHANGELOG.md

@@ -8,6 +8,7 @@ file.  This project adheres to [Semantic Versioning](http://semver.org/).
 ### New features
 
 * Add `SequenceNumber` function to `Transaction`.
+* Add `AddSignatureDecorated` function to `Transaction`.
 
 ### Bug Fix
 

txnbuild/transaction.go

@@ -76,6 +76,13 @@ func concatSignatures(
 	return extended, nil
 }
 
+func concatSignatureDecorated(e xdr.TransactionEnvelope, signatures []xdr.DecoratedSignature, newSignatures []xdr.DecoratedSignature) ([]xdr.DecoratedSignature, error) {
+	extended := make([]xdr.DecoratedSignature, len(signatures)+len(newSignatures))
+	copy(extended, signatures)
+	copy(extended[len(signatures):], newSignatures)
+	return extended, nil
+}
+
 func concatSignatureBase64(e xdr.TransactionEnvelope, signatures []xdr.DecoratedSignature, networkStr, publicKey, signature string) ([]xdr.DecoratedSignature, error) {
 	if signature == "" {
 		return nil, errors.New("signature not presented")
@@ -305,6 +312,17 @@ func (t *Transaction) SignHashX(preimage []byte) (*Transaction, error) {
 	return t.clone(extendedSignatures), nil
 }
 
+// AddSignatureDecorated returns a new Transaction instance which extends the current instance
+// with an additional decorated signature(s).
+func (t *Transaction) AddSignatureDecorated(signature ...xdr.DecoratedSignature) (*Transaction, error) {
+	extendedSignatures, err := concatSignatureDecorated(t.envelope, t.Signatures(), signature)
+	if err != nil {
+		return nil, err
+	}
+
+	return t.clone(extendedSignatures), nil
+}
+
 // AddSignatureBase64 returns a new Transaction instance which extends the current instance
 // with an additional signature derived from the given base64-encoded signature.
 func (t *Transaction) AddSignatureBase64(network, publicKey, signature string) (*Transaction, error) {

txnbuild/transaction_test.go

@@ -1577,6 +1577,113 @@ func TestSignWithSecretKey(t *testing.T) {
 	assert.Equal(t, expected, actual, "base64 xdr should match")
 }
 
+func TestAddSignatureDecorated(t *testing.T) {
+	kp0 := newKeypair0()
+	kp1 := newKeypair1()
+	txSource := NewSimpleAccount(kp0.Address(), int64(9605939170639897))
+	tx1Source := NewSimpleAccount(kp0.Address(), int64(9605939170639897))
+	createAccount := CreateAccount{
+		Destination:   "GCCOBXW2XQNUSL467IEILE6MMCNRR66SSVL4YQADUNYYNUVREF3FIV2Z",
+		Amount:        "10",
+		SourceAccount: kp1.Address(),
+	}
+
+	expected, err := newSignedTransaction(
+		TransactionParams{
+			SourceAccount:        &txSource,
+			IncrementSequenceNum: true,
+			Operations:           []Operation{&createAccount},
+			BaseFee:              MinBaseFee,
+			Timebounds:           NewInfiniteTimeout(),
+		},
+		network.TestNetworkPassphrase,
+		kp0, kp1,
+	)
+	assert.NoError(t, err)
+
+	tx1, err := NewTransaction(
+		TransactionParams{
+			SourceAccount:        &tx1Source,
+			IncrementSequenceNum: true,
+			Operations:           []Operation{&createAccount},
+			BaseFee:              MinBaseFee,
+			Timebounds:           NewInfiniteTimeout(),
+		},
+	)
+	assert.NoError(t, err)
+
+	// Same if signatures added separately.
+	{
+		var tx1sigs1 *Transaction
+		tx1sigs1, err = tx1.AddSignatureDecorated(
+			xdr.DecoratedSignature{
+				Hint: kp0.Hint(),
+				Signature: func() xdr.Signature {
+					var sigBytes []byte
+					sigBytes, err = base64.StdEncoding.DecodeString("TVogR6tbrWLnOc1BsP/j+Qrxpja2NWNgeRIwujECYscRdMG7AMtnb3dkCT7sqlbSM0TTzlRh7G+BcVocYBtqBw==")
+					if err != nil {
+						require.NoError(t, err)
+					}
+					return xdr.Signature(sigBytes)
+				}(),
+			},
+		)
+		assert.NoError(t, err)
+		tx1sigs1, err = tx1sigs1.AddSignatureDecorated(
+			xdr.DecoratedSignature{
+				Hint: kp1.Hint(),
+				Signature: func() xdr.Signature {
+					var sigBytes []byte
+					sigBytes, err = base64.StdEncoding.DecodeString("Iy77JteoW/FbeiuViZpgTyvrHP4BnBOeyVOjrdb5O/MpEMwcSlYXAkCBqPt4tBDil4jIcDDLhm7TsN6aUBkIBg==")
+					if err != nil {
+						require.NoError(t, err)
+					}
+					return xdr.Signature(sigBytes)
+				}(),
+			},
+		)
+		assert.NoError(t, err)
+		var actual string
+		actual, err = tx1sigs1.Base64()
+		assert.NoError(t, err)
+		assert.Equal(t, expected, actual, "base64 xdr should match")
+	}
+
+	// Same if signatures added together.
+	{
+		var tx1sigs2 *Transaction
+		tx1sigs2, err = tx1.AddSignatureDecorated(
+			xdr.DecoratedSignature{
+				Hint: kp0.Hint(),
+				Signature: func() xdr.Signature {
+					var sigBytes []byte
+					sigBytes, err = base64.StdEncoding.DecodeString("TVogR6tbrWLnOc1BsP/j+Qrxpja2NWNgeRIwujECYscRdMG7AMtnb3dkCT7sqlbSM0TTzlRh7G+BcVocYBtqBw==")
+					if err != nil {
+						require.NoError(t, err)
+					}
+					return xdr.Signature(sigBytes)
+				}(),
+			},
+			xdr.DecoratedSignature{
+				Hint: kp1.Hint(),
+				Signature: func() xdr.Signature {
+					var sigBytes []byte
+					sigBytes, err = base64.StdEncoding.DecodeString("Iy77JteoW/FbeiuViZpgTyvrHP4BnBOeyVOjrdb5O/MpEMwcSlYXAkCBqPt4tBDil4jIcDDLhm7TsN6aUBkIBg==")
+					if err != nil {
+						require.NoError(t, err)
+					}
+					return xdr.Signature(sigBytes)
+				}(),
+			},
+		)
+		assert.NoError(t, err)
+		var actual string
+		actual, err = tx1sigs2.Base64()
+		assert.NoError(t, err)
+		assert.Equal(t, expected, actual, "base64 xdr should match")
+	}
+}
+
 func TestAddSignatureBase64(t *testing.T) {
 	kp0 := newKeypair0()
 	kp1 := newKeypair1()