refactor: transfer and transferfrom to save constrains for simpler ca…

…ses (#7013)

Splits the `transfer` into `transfer` and `transfer_from`.
`transfer_from` behaves as our old `transfer` and is expected to be
useful for contracts pulling funds, while `transfer` is useful for
pushing funds around.

The `transfer` only take `to` and `amount` and don't have any authwit
implementation anymore. This means a reduction of a `call` for the case
where funds are pushed.

noir-projects/noir-contracts/contracts/app_subscription_contract/src/main.nr

@@ -103,7 +103,7 @@ contract AppSubscription {
     ) {
         assert(tx_count as u64 <= SUBSCRIPTION_TXS as u64);
 
-        Token::at(storage.subscription_token_address.read_private()).transfer(
+        Token::at(storage.subscription_token_address.read_private()).transfer_from(
             context.msg_sender(),
             storage.subscription_recipient_address.read_private(),
             storage.subscription_price.read_private(),

noir-projects/noir-contracts/contracts/crowdfunding_contract/src/main.nr

@@ -79,7 +79,7 @@ contract Crowdfunding {
         // docs:start:do-transfer
         // 2) Transfer the donation tokens from donor to this contract
         let donor = context.msg_sender();
-        Token::at(storage.donation_token.read_private()).transfer(donor, context.this_address(), amount as Field, 0).call(&mut context);
+        Token::at(storage.donation_token.read_private()).transfer_from(donor, context.this_address(), amount as Field, 0).call(&mut context);
         // docs:end:do-transfer
 
         let header = context.get_header();
@@ -100,7 +100,7 @@ contract Crowdfunding {
         assert(context.msg_sender() == operator_address, "Not an operator");
 
         // 2) Transfer the donation tokens from this contract to the operator
-        Token::at(storage.donation_token.read_private()).transfer(context.this_address(), operator_address, amount as Field, 0).call(&mut context);
+        Token::at(storage.donation_token.read_private()).transfer(operator_address, amount as Field).call(&mut context);
 
         // 3) Emit an unencrypted event so that anyone can audit how much the operator has withdrawn
         let event = WithdrawalProcessed { amount, who: operator_address };

noir-projects/noir-contracts/contracts/escrow_contract/src/main.nr

@@ -26,12 +26,11 @@ contract Escrow {
     // Withdraws balance. Requires that msg.sender is the owner.
     #[aztec(private)]
     fn withdraw(token: AztecAddress, amount: Field, recipient: AztecAddress) {
-        let this = context.this_address();
         let sender = context.msg_sender();
 
         let note = storage.owner.get_note();
         assert(note.address == sender);
 
-        Token::at(token).transfer(this, recipient, amount, 0).call(&mut context);
+        Token::at(token).transfer(recipient, amount).call(&mut context);
     }
 }

noir-projects/noir-contracts/contracts/token_contract/src/main.nr

@@ -310,7 +310,24 @@ contract Token {
 
     // docs:start:transfer
     #[aztec(private)]
-    fn transfer(from: AztecAddress, to: AztecAddress, amount: Field, nonce: Field) {
+    fn transfer(to: AztecAddress, amount: Field) {
+        let from = context.msg_sender();
+
+        // By fetching the keys here, we can avoid doing an extra read from the storage, since from_ovpk would
+        // be needed twice.
+        let header = context.get_header();
+        let from_ovpk = header.get_ovpk_m(&mut context, from);
+        let from_ivpk = header.get_ivpk_m(&mut context, from);
+        let to_ivpk = header.get_ivpk_m(&mut context, to);
+
+        let amount = U128::from_integer(amount);
+        storage.balances.sub(from, amount).emit(encode_and_encrypt_with_keys(&mut context, from_ovpk, from_ivpk));
+        storage.balances.add(to, amount).emit(encode_and_encrypt_with_keys(&mut context, from_ovpk, to_ivpk));
+    }
+    // docs:end:transfer
+
+    #[aztec(private)]
+    fn transfer_from(from: AztecAddress, to: AztecAddress, amount: Field, nonce: Field) {
         // docs:start:assert_current_call_valid_authwit
         if (!from.eq(context.msg_sender())) {
             assert_current_call_valid_authwit(&mut context, from);
@@ -334,7 +351,6 @@ contract Token {
         // docs:end:increase_private_balance
         storage.balances.add(to, amount).emit(encode_and_encrypt_with_keys(&mut context, from_ovpk, to_ivpk));
     }
-    // docs:end:transfer
 
     // docs:start:burn
     #[aztec(private)]

yarn-project/aztec/src/examples/token.ts

@@ -73,7 +73,7 @@ async function main() {
 
   // We will now transfer tokens from Alice to Bob
   logger.info(`Transferring ${TRANSFER_AMOUNT} tokens from Alice to Bob...`);
-  await tokenAlice.methods.transfer(alice, bob, TRANSFER_AMOUNT, 0).send().wait();
+  await tokenAlice.methods.transfer(bob, TRANSFER_AMOUNT).send().wait();
 
   // Check the new balances
   const aliceBalance = await tokenAlice.methods.balance_of_private(alice).simulate();

yarn-project/end-to-end/src/benchmarks/bench_prover.test.ts

@@ -161,7 +161,7 @@ describe('benchmarks/proving', () => {
 
     const fnCalls = [
       (await getTokenContract(0)).methods.transfer_public(schnorrWalletAddress.address, recipient.address, 1000, 0),
-      (await getTokenContract(1)).methods.transfer(schnorrWalletAddress.address, recipient.address, 1000, 0),
+      (await getTokenContract(1)).methods.transfer(recipient.address, 1000),
       // (await getTestContractOnPXE(2)).methods.emit_unencrypted(43),
       // (await getTestContractOnPXE(3)).methods.create_l2_to_l1_message_public(45, 46, EthAddress.random()),
     ];

yarn-project/end-to-end/src/benchmarks/bench_tx_size_fees.test.ts

@@ -89,7 +89,7 @@ describe('benchmarks/tx_size_fees', () => {
       const paymentMethod = createPaymentMethod();
       const gasSettings = GasSettings.default();
       const tx = await token.methods
-        .transfer(aliceWallet.getAddress(), bobAddress, 1n, 0)
+        .transfer(bobAddress, 1n)
         .send({ fee: paymentMethod ? { gasSettings, paymentMethod } : undefined })
         .wait();
 

yarn-project/end-to-end/src/composed/e2e_persistence.test.ts

@@ -151,7 +151,7 @@ describe('Aztec persistence', () => {
 
       const initialOwnerBalance = await contract.methods.balance_of_private(ownerWallet.getAddress()).simulate();
 
-      await contract.methods.transfer(ownerWallet.getAddress(), otherWallet.getAddress(), 500n, Fr.ZERO).send().wait();
+      await contract.methods.transfer(otherWallet.getAddress(), 500n).send().wait();
 
       const [ownerBalance, targetBalance] = await Promise.all([
         contract.methods.balance_of_private(ownerWallet.getAddress()).simulate(),

yarn-project/end-to-end/src/composed/e2e_sandbox_example.test.ts

@@ -122,7 +122,7 @@ describe('e2e_sandbox_example', () => {
     // We will now transfer tokens from ALice to Bob
     const transferQuantity = 543n;
     logger.info(`Transferring ${transferQuantity} tokens from Alice to Bob...`);
-    await tokenContractAlice.methods.transfer(alice, bob, transferQuantity, 0).send().wait();
+    await tokenContractAlice.methods.transfer(bob, transferQuantity).send().wait();
 
     // Check the new balances
     aliceBalance = await tokenContractAlice.methods.balance_of_private(alice).simulate();

yarn-project/end-to-end/src/e2e_2_pxes.test.ts

@@ -139,10 +139,7 @@ describe('e2e_2_pxes', () => {
 
     // Transfer funds from A to B via PXE A
     const contractWithWalletA = await TokenContract.at(token.address, walletA);
-    await contractWithWalletA.methods
-      .transfer(walletA.getAddress(), walletB.getAddress(), transferAmount1, 0)
-      .send()
-      .wait();
+    await contractWithWalletA.methods.transfer(walletB.getAddress(), transferAmount1).send().wait();
 
     // Check balances and logs are as expected
     await expectTokenBalance(walletA, token.address, walletA.getAddress(), initialBalance - transferAmount1);
@@ -151,10 +148,7 @@ describe('e2e_2_pxes', () => {
 
     // Transfer funds from B to A via PXE B
     const contractWithWalletB = await TokenContract.at(token.address, walletB);
-    await contractWithWalletB.methods
-      .transfer(walletB.getAddress(), walletA.getAddress(), transferAmount2, 0)
-      .send()
-      .wait({ interval: 0.1 });
+    await contractWithWalletB.methods.transfer(walletA.getAddress(), transferAmount2).send().wait({ interval: 0.1 });
 
     // Check balances and logs are as expected
     await expectTokenBalance(
@@ -281,10 +275,7 @@ describe('e2e_2_pxes', () => {
 
     // Transfer funds from A to B via PXE A
     const contractWithWalletA = await TokenContract.at(tokenAddress, walletA);
-    await contractWithWalletA.methods
-      .transfer(walletA.getAddress(), walletB.getAddress(), transferAmount1, 0)
-      .send()
-      .wait();
+    await contractWithWalletA.methods.transfer(walletB.getAddress(), transferAmount1).send().wait();
 
     // now add the contract and check balances
     await pxeB.registerContract(token);
@@ -316,17 +307,11 @@ describe('e2e_2_pxes', () => {
 
     // Transfer funds from A to Shared Wallet via PXE A
     const contractWithWalletA = await TokenContract.at(token.address, walletA);
-    await contractWithWalletA.methods
-      .transfer(walletA.getAddress(), sharedAccountAddress.address, transferAmount1, 0)
-      .send()
-      .wait();
+    await contractWithWalletA.methods.transfer(sharedAccountAddress.address, transferAmount1).send().wait();
 
     // Now send funds from Shared Wallet to B via PXE A
     const contractWithSharedWalletA = await TokenContract.at(token.address, sharedWalletOnA);
-    await contractWithSharedWalletA.methods
-      .transfer(sharedAccountAddress.address, walletB.getAddress(), transferAmount2, 0)
-      .send()
-      .wait();
+    await contractWithSharedWalletA.methods.transfer(walletB.getAddress(), transferAmount2).send().wait();
 
     // check balances from PXE-A's perspective
     await expectTokenBalance(walletA, token.address, walletA.getAddress(), initialBalance - transferAmount1);

yarn-project/end-to-end/src/e2e_crowdfunding_and_claim.test.ts

@@ -209,7 +209,7 @@ describe('e2e_crowdfunding_and_claim', () => {
     {
       const action = donationToken
         .withWallet(donorWallets[0])
-        .methods.transfer(donorWallets[0].getAddress(), crowdfundingContract.address, donationAmount, 0);
+        .methods.transfer_from(donorWallets[0].getAddress(), crowdfundingContract.address, donationAmount, 0);
       const witness = await donorWallets[0].createAuthWit({ caller: crowdfundingContract.address, action });
       await donorWallets[0].addAuthWitness(witness);
     }
@@ -275,7 +275,7 @@ describe('e2e_crowdfunding_and_claim', () => {
     {
       const action = donationToken
         .withWallet(donorWallets[1])
-        .methods.transfer(donorWallets[1].getAddress(), crowdfundingContract.address, donationAmount, 0);
+        .methods.transfer_from(donorWallets[1].getAddress(), crowdfundingContract.address, donationAmount, 0);
       const witness = await donorWallets[1].createAuthWit({ caller: crowdfundingContract.address, action });
       await donorWallets[1].addAuthWitness(witness);
     }
@@ -368,7 +368,7 @@ describe('e2e_crowdfunding_and_claim', () => {
     {
       const action = donationToken
         .withWallet(donorWallets[1])
-        .methods.transfer(donorWallets[1].getAddress(), crowdfundingContract.address, donationAmount, 0);
+        .methods.transfer_from(donorWallets[1].getAddress(), crowdfundingContract.address, donationAmount, 0);
       const witness = await donorWallets[1].createAuthWit({ caller: crowdfundingContract.address, action });
       await donorWallets[1].addAuthWitness(witness);
     }

yarn-project/end-to-end/src/e2e_escrow_contract.test.ts

@@ -130,7 +130,7 @@ describe('e2e_escrow_contract', () => {
     await expectBalance(owner, 50n);
 
     const actions = [
-      token.methods.transfer(owner, recipient, 10, 0).request(),
+      token.methods.transfer(recipient, 10).request(),
       escrowContract.methods.withdraw(token.address, 20, recipient).request(),
     ];
 

yarn-project/end-to-end/src/e2e_fees/dapp_subscription.test.ts

@@ -192,7 +192,7 @@ describe('e2e_fees dapp_subscription', () => {
 
   async function subscribe(paymentMethod: FeePaymentMethod, blockDelta: number = 5, txCount: number = 4) {
     const nonce = Fr.random();
-    const action = bananaCoin.methods.transfer(aliceAddress, bobAddress, t.SUBSCRIPTION_AMOUNT, nonce);
+    const action = bananaCoin.methods.transfer_from(aliceAddress, bobAddress, t.SUBSCRIPTION_AMOUNT, nonce);
     await aliceWallet.createAuthWit({ caller: subscriptionContract.address, action });
 
     return subscriptionContract

yarn-project/end-to-end/src/e2e_fees/native_payments.test.ts

@@ -78,7 +78,7 @@ describe('e2e_fees native_payments', () => {
     it('sends tx with native fee payment method with no public calls', async () => {
       const initialBalance = await gasTokenContract.methods.balance_of_public(aliceAddress).simulate();
       const { transactionFee } = await bananaCoin.methods
-        .transfer(aliceAddress, bobAddress, 1n, 0n)
+        .transfer(bobAddress, 1n)
         .send({ fee: { gasSettings, paymentMethod } })
         .wait();
       expect(transactionFee).toBeGreaterThan(0n);

yarn-project/end-to-end/src/e2e_fees/private_payments.test.ts

@@ -105,7 +105,7 @@ describe('e2e_fees private_payment', () => {
      * this is expected to squash notes and nullifiers
      */
     const transferAmount = 5n;
-    const interaction = bananaCoin.methods.transfer(aliceAddress, bobAddress, transferAmount, 0n);
+    const interaction = bananaCoin.methods.transfer(bobAddress, transferAmount);
     const localTx = await interaction.prove({
       fee: {
         gasSettings,
@@ -313,7 +313,7 @@ describe('e2e_fees private_payment', () => {
      *   create transparent note with RefundAmount
      */
     const tx = await new BatchCall(aliceWallet, [
-      bananaCoin.methods.transfer(aliceAddress, bobAddress, privateTransfer, 0n).request(),
+      bananaCoin.methods.transfer(bobAddress, privateTransfer).request(),
       bananaCoin.methods.shield(aliceAddress, shieldedBananas, shieldSecretHash, 0n).request(),
     ])
       .send({

yarn-project/end-to-end/src/e2e_key_rotation.test.ts

@@ -159,7 +159,7 @@ describe('e2e_key_rotation', () => {
     const transfer1Amount = 654n;
     {
       ({ txHash: txHashTransfer1 } = await contractWithWalletA.methods
-        .transfer(walletA.getAddress(), walletB.getAddress(), transfer1Amount, 0)
+        .transfer(walletB.getAddress(), transfer1Amount)
         .send()
         .wait());
 
@@ -190,7 +190,7 @@ describe('e2e_key_rotation', () => {
     const transfer2Amount = 321n;
     {
       ({ txHash: txHashTransfer2 } = await contractWithWalletA.methods
-        .transfer(walletA.getAddress(), walletB.getAddress(), transfer2Amount, 0)
+        .transfer(walletB.getAddress(), transfer2Amount)
         .send()
         .wait());
 
@@ -225,7 +225,7 @@ describe('e2e_key_rotation', () => {
     // --> this way we verify that it's possible to obtain both keys via oracles
     {
       await contractWithWalletB.methods
-        .transfer(walletB.getAddress(), walletA.getAddress(), transfer1Amount + transfer2Amount, 0)
+        .transfer(walletA.getAddress(), transfer1Amount + transfer2Amount)
         .send()
         .wait();
 

yarn-project/end-to-end/src/e2e_multiple_accounts_1_enc_key.test.ts

@@ -103,7 +103,7 @@ describe('e2e_multiple_accounts_1_enc_key', () => {
 
     const contractWithWallet = await TokenContract.at(tokenAddress, wallets[senderIndex]);
 
-    await contractWithWallet.methods.transfer(sender, receiver, transferAmount, 0).send().wait();
+    await contractWithWallet.methods.transfer(receiver, transferAmount).send().wait();
 
     for (let i = 0; i < expectedBalances.length; i++) {
       await expectBalance(i, expectedBalances[i]);

yarn-project/end-to-end/src/e2e_prover/full.test.ts

@@ -34,12 +34,7 @@ describe('full_prover', () => {
       const privateBalance = await provenAssets[0].methods.balance_of_private(accounts[0].address).simulate();
       const privateSendAmount = privateBalance / 2n;
       expect(privateSendAmount).toBeGreaterThan(0n);
-      const privateInteraction = provenAssets[0].methods.transfer(
-        accounts[0].address,
-        accounts[1].address,
-        privateSendAmount,
-        0,
-      );
+      const privateInteraction = provenAssets[0].methods.transfer(accounts[1].address, privateSendAmount);
 
       const publicBalance = await provenAssets[1].methods.balance_of_public(accounts[0].address).simulate();
       const publicSendAmount = publicBalance / 2n;
@@ -94,7 +89,7 @@ describe('full_prover', () => {
   );
 
   it('rejects txs with invalid proofs', async () => {
-    const privateInteraction = t.fakeProofsAsset.methods.transfer(accounts[0].address, accounts[1].address, 1, 0);
+    const privateInteraction = t.fakeProofsAsset.methods.transfer(accounts[1].address, 1);
     const publicInteraction = t.fakeProofsAsset.methods.transfer_public(accounts[0].address, accounts[1].address, 1, 0);
 
     const sentPrivateTx = privateInteraction.send();

yarn-project/end-to-end/src/e2e_prover/with_padding.test.ts

@@ -31,12 +31,7 @@ describe('full_prover_with_padding_tx', () => {
       const privateBalance = await provenAssets[0].methods.balance_of_private(accounts[0].address).simulate();
       const privateSendAmount = privateBalance / 2n;
       expect(privateSendAmount).toBeGreaterThan(0n);
-      const privateInteraction = provenAssets[0].methods.transfer(
-        accounts[0].address,
-        accounts[1].address,
-        privateSendAmount,
-        0,
-      );
+      const privateInteraction = provenAssets[0].methods.transfer(accounts[1].address, privateSendAmount);
 
       const privateTx = await privateInteraction.prove();