test: add tests for return values on different StreamUtilities functions

packages/contracts/contracts/mocks/StreamUtilitiesMock.sol

@@ -7,6 +7,11 @@ import '../StreamUtilities.sol';
 contract StreamUtilitiesMock {
     // The provided struct object is stored here as StreamUtilities expects a storage variable.
     Types.AztecStream public stream;
+    event ValidateRatioProof(bytes32 withdrawalNoteHash);
+    event ValidateJoinSplitProof(bytes32 withdrawalNoteHash);
+    event ProcessDeposit(bytes32 streamNoteHash);
+    event ProcessWithdrawal(bytes32 newStreamNoteHash);
+    event ProcessCancellation(bool cancellationSuccess);
 
     function getRatio(bytes memory _proofData)
         public
@@ -23,13 +28,13 @@ contract StreamUtilitiesMock {
         Types.AztecStream memory _stream
     ) public returns (bytes32) {
         stream = _stream;
-        return
-            StreamUtilities._validateRatioProof(
-                _aceContractAddress,
-                _proof1,
-                _withdrawDuration,
-                stream
-            );
+        bytes32 withdrawalNoteHash = StreamUtilities._validateRatioProof(
+            _aceContractAddress,
+            _proof1,
+            _withdrawDuration,
+            stream
+        );
+        emit ValidateRatioProof(withdrawalNoteHash);
     }
 
     function validateJoinSplitProof(
@@ -39,7 +44,7 @@ contract StreamUtilitiesMock {
         Types.AztecStream memory _stream
     ) public returns (bytes memory) {
         stream = _stream;
-        return
+        bytes memory proofOutputs =
             StreamUtilities._validateJoinSplitProof(
                 _aceContractAddress,
                 _proof2,
@@ -56,15 +61,15 @@ contract StreamUtilitiesMock {
         address _recipient,
         address _tokenAddress
     ) public returns (bytes32) {
-        return
-            StreamUtilities._processDeposit(
-                _proof,
-                _proofSignature,
-                _aceContractAddress,
-                _sender,
-                _recipient,
-                _tokenAddress
-            );
+        bytes32 newStreamNoteHash = StreamUtilities._processDeposit(
+            _proof,
+            _proofSignature,
+            _aceContractAddress,
+            _sender,
+            _recipient,
+            _tokenAddress
+        );
+        emit ProcessDeposit(newStreamNoteHash);
     }
 
     function processWithdrawal(
@@ -74,13 +79,13 @@ contract StreamUtilitiesMock {
         Types.AztecStream memory _stream
     ) public returns (bytes32) {
         stream = _stream;
-        return
-            StreamUtilities._processWithdrawal(
-                _aceContractAddress,
-                _proof2,
-                _withdrawalNoteHash,
-                stream
-            );
+        bytes32 newStreamNoteHash = StreamUtilities._processWithdrawal(
+            _aceContractAddress,
+            _proof2,
+            _withdrawalNoteHash,
+            stream
+        );
+        emit ProcessWithdrawal(newStreamNoteHash);
     }
 
     function processCancellation(
@@ -90,12 +95,13 @@ contract StreamUtilitiesMock {
         Types.AztecStream memory _stream
     ) public returns (bool) {
         stream = _stream;
-        return
+        bool cancellationSuccess =
             StreamUtilities._processCancellation(
                 _aceContractAddress,
                 _proof2,
                 _proof1OutputNotes,
                 stream
             );
+        emit ProcessCancellation(cancellationSuccess);
     }
 }

packages/contracts/test/StreamUtilities/processCancellation.js

@@ -159,4 +159,41 @@ describe('StreamUtilities - processCancellation', function () {
             .to.emit(zkAsset, 'DestroyNote')
             .withArgs(streamUtilitiesMock.address, streamNote.noteHash);
     });
+
+    it('transfers the zkAssets to the sender and recipient and returns true', async function () {
+        const withdrawalNote = await createNote(
+            streamNote.k.toNumber() / 4,
+            recipient.address,
+            [recipient.address]
+        );
+
+        const refundNote = await createNote(
+            (streamNote.k.toNumber() * 3) / 4,
+            sender.address,
+            [sender.address]
+        );
+
+        const proof = new JoinSplitProof(
+            [streamNote],
+            [withdrawalNote, refundNote],
+            streamUtilitiesMock.address,
+            0,
+            sender.address
+        );
+
+        const proofData = proof.encodeABI(zkAsset.address);
+
+        await expect(
+            streamUtilitiesMock.processCancellation(
+                ace.address,
+                proofData,
+                withdrawalNote.noteHash,
+                streamObject
+            )
+        )
+            .to.emit(zkAsset, 'DestroyNote')
+            .withArgs(streamUtilitiesMock.address, streamNote.noteHash)
+            .and.emit(streamUtilitiesMock, 'ProcessCancellation')
+            .withArgs(true);
+    });
 });

packages/contracts/test/StreamUtilities/processDeposit.js

@@ -209,8 +209,8 @@ describe('StreamUtilities - processDeposit', function () {
             )
         ).to.be.revertedWith("stream recipient can't view stream note");
     });
-    it('transfers the zkAssets to the contract', async function () {
-        const { depositProof } = await createStreamDepositProof(
+    it('transfers the zkAssets to the contract and returns the new stream note hash', async function () {
+        const { depositProof, streamNote } = await createStreamDepositProof(
             [depositOutputNote],
             streamUtilitiesMock.address,
             sender.address,
@@ -235,8 +235,8 @@ describe('StreamUtilities - processDeposit', function () {
             )
         )
             .to.emit(zkAsset, 'DestroyNote')
-            .withArgs(sender.address, depositOutputNote.noteHash);
+            .withArgs(sender.address, depositOutputNote.noteHash)
+            .and.emit(streamUtilitiesMock, 'ProcessDeposit')
+            .withArgs(streamNote.noteHash);
     });
-
-    it('returns the hash of the new stream note');
 });

packages/contracts/test/StreamUtilities/processWithdrawal.js

@@ -187,7 +187,7 @@ describe('StreamUtilities - processWithdrawal', function () {
         ).to.be.revertedWith("stream recipient can't view new stream note");
     });
 
-    it('transfers the zkAssets to the sender and recipient', async function () {
+    it('transfers the zkAssets to the sender and recipient and returns the hash of the new stream note', async function () {
         const withdrawalNote = await createNote(
             streamNote.k.toNumber() / 4,
             recipient.address,
@@ -219,8 +219,8 @@ describe('StreamUtilities - processWithdrawal', function () {
             )
         )
             .to.emit(zkAsset, 'DestroyNote')
-            .withArgs(streamUtilitiesMock.address, streamNote.noteHash);
+            .withArgs(streamUtilitiesMock.address, streamNote.noteHash)
+            .and.emit(streamUtilitiesMock, 'ProcessWithdrawal')
+            .withArgs(refundNote.noteHash);
     });
-
-    it('returns the hash of the new stream note');
 });

packages/contracts/test/StreamUtilities/validateRatioProof.js

@@ -143,5 +143,62 @@ describe('StreamUtilities - validateRatioProof', function () {
         ).to.be.revertedWith('incorrect notional note in proof 1');
     });
 
-    it('returns withdrawal note hash');
+    it('returns withdrawal note hash', async function () {
+        const inputNoteValue = 1000;
+
+        const streamTotalDuration = 100;
+        const withdrawalDuration = 10;
+
+        // We may then withdraw 1/10th of the note's value, i.e. 100
+        const withdrawNoteValue = 100;
+        const remainderNoteValue = 0;
+        const ratioNumerator = 1;
+        const ratioDenominator = 10;
+
+        const inputNote = await createNote(
+            inputNoteValue,
+            streamUtilitiesMock.address,
+            [sender.address]
+        );
+
+        const withdrawNote = await createNote(
+            withdrawNoteValue,
+            sender.address,
+            [sender.address]
+        );
+
+        const remainderNote = await createNote(
+            remainderNoteValue,
+            streamUtilitiesMock.address,
+            [sender.address]
+        );
+
+        const proofData = new DividendProof(
+            inputNote,
+            remainderNote,
+            withdrawNote,
+            streamUtilitiesMock.address,
+            ratioDenominator,
+            ratioNumerator
+        ).encodeABI();
+
+        const streamObject = {
+            ...streamObjectTemplate,
+            noteHash: inputNote.noteHash,
+            startTime: 0,
+            lastWithdrawTime: 0,
+            stopTime: streamTotalDuration,
+        };
+
+        await expect(
+            streamUtilitiesMock.validateRatioProof(
+                ace.address,
+                proofData,
+                withdrawalDuration,
+                streamObject
+            )
+        )
+            .to.emit(streamUtilitiesMock, 'ValidateRatioProof')
+            .withArgs(withdrawNote.noteHash);
+    });
 });