fix(wallet): resolve only the own signed portions of the witness set

"Only the portions of the witness set that were signed as a result
of this call are returned to encourage dApps to verify the contents
returned by this endpoint while building the final transaction."

Author: mkazlauskas

packages/wallet/src/cip30.ts

@@ -469,7 +469,10 @@ const baseCip30WalletApi = (
           );
         }
 
-        const cbor = Serialization.TransactionWitnessSet.fromCore({ signatures }).toCbor();
+        const ownSignatures = new Map(
+          [...signatures.entries()].filter(([pubKey]) => !coreTx.witness.signatures.has(pubKey))
+        );
+        const cbor = Serialization.TransactionWitnessSet.fromCore({ signatures: ownSignatures }).toCbor();
         return Promise.resolve(cbor);
       } catch (error) {
         if (error instanceof TxSignError) {

packages/wallet/test/integration/cip30mapping.test.ts

@@ -512,9 +512,19 @@ describe('cip30', () => {
           hexTx = Serialization.Transaction.fromCore(finalizedTx).toCbor();
         });
 
-        it('resolves with TransactionWitnessSet', async () => {
-          const cip30witnessSet = await api.signTx(context, hexTx);
-          expect(() => Serialization.TransactionWitnessSet.fromCbor(HexBlob(cip30witnessSet))).not.toThrow();
+        it('resolves own signatures with TransactionWitnessSet', async () => {
+          const cip30witnessSetCbor = await api.signTx(context, hexTx);
+          const cip30witnessSet = Serialization.TransactionWitnessSet.fromCbor(HexBlob(cip30witnessSetCbor));
+          const resolvedSignedByKeys = cip30witnessSet
+            .vkeys()!
+            .toCore()
+            .map(([pubKey]) => pubKey);
+          const preExistingSignatures = finalizedTx.witness.signatures.entries();
+
+          expect(resolvedSignedByKeys.length).toBeGreaterThan(0);
+          for (const [preExistingKey] of preExistingSignatures) {
+            expect(resolvedSignedByKeys).not.toContain(preExistingKey);
+          }
         });
 
         it('passes through sender from dapp connector context', async () => {