Add send API to zkApp and Party classes

src/examples/simple-zkapp-payment.ts

@@ -0,0 +1,131 @@
+import {
+  isReady,
+  method,
+  Mina,
+  Party,
+  PrivateKey,
+  SmartContract,
+  PublicKey,
+  UInt64,
+  shutdown,
+  DeployArgs,
+  Permissions,
+} from 'snarkyjs';
+
+await isReady;
+
+class SendMINAExample extends SmartContract {
+  deploy(args: DeployArgs) {
+    super.deploy(args);
+    this.setPermissions({
+      ...Permissions.default(),
+      editState: Permissions.proofOrSignature(),
+      editSequenceState: Permissions.proofOrSignature(),
+    });
+    this.balance.addInPlace(UInt64.fromNumber(initialBalance));
+  }
+
+  @method sendMINA(receiverAddress: PublicKey, amount: UInt64) {
+    this.send({
+      to: receiverAddress,
+      amount,
+    });
+  }
+}
+
+let Local = Mina.LocalBlockchain();
+Mina.setActiveInstance(Local);
+
+// a test account that pays all the fees, and puts additional funds into the zkapp
+let feePayer = Local.testAccounts[0].privateKey;
+
+// the zkapp account
+let zkappKey = PrivateKey.random();
+let zkappAddress = zkappKey.toPublicKey();
+
+let account1Key = PrivateKey.random();
+let account1Address = account1Key.toPublicKey();
+
+let account2Key = PrivateKey.random();
+let account2Address = account2Key.toPublicKey();
+
+let zkapp = new SendMINAExample(zkappAddress);
+let initialBalance = 10_000_000_000;
+let tx;
+
+console.log('deploy');
+tx = await Mina.transaction(feePayer, () => {
+  Party.fundNewAccount(feePayer, { initialBalance });
+  zkapp.deploy({ zkappKey });
+});
+tx.send();
+
+console.log(`zkApp balance: ${Mina.getBalance(zkappAddress)} MINA`);
+
+console.log('----------MINA sending----------');
+tx = await Local.transaction(feePayer, () => {
+  Party.fundNewAccount(feePayer);
+  zkapp.sendMINA(account1Address, UInt64.from(1_000_000));
+  zkapp.sign(zkappKey);
+});
+tx.send();
+
+console.log(`zkApp balance: ${Mina.getBalance(zkappAddress)} MINA`);
+console.log(
+  `account1Address balance: ${Mina.getBalance(account1Address)} MINA`
+);
+
+console.log('----------MINA sending (with signed)----------');
+tx = await Local.transaction(feePayer, () => {
+  Party.fundNewAccount(feePayer);
+  let party = Party.createSigned(zkappKey);
+  party.send({ to: account2Address, amount: UInt64.from(1_000_000) });
+  zkapp.sign(zkappKey);
+  zkapp.account.nonce.assertEquals(zkapp.account.nonce.get().add(1));
+});
+tx.send();
+
+console.log(`zkApp balance: ${Mina.getBalance(zkappAddress)} MINA`);
+console.log(
+  `account1Address balance: ${Mina.getBalance(account1Address)} MINA`
+);
+console.log(
+  `account2Address balance: ${Mina.getBalance(account2Address)} MINA`
+);
+
+console.log('----------MINA sending (with unsigned)----------');
+tx = await Local.transaction(feePayer, () => {
+  let party = Party.createUnsigned(zkappAddress);
+  party.signInPlace(zkappKey);
+  party.send({ to: account2Address, amount: UInt64.from(1_000_000) });
+  zkapp.sign(zkappKey);
+  zkapp.account.nonce.assertEquals(zkapp.account.nonce.get().add(1));
+});
+tx.send();
+
+console.log(`zkApp balance: ${Mina.getBalance(zkappAddress)} MINA`);
+console.log(
+  `account1Address balance: ${Mina.getBalance(account1Address)} MINA`
+);
+console.log(
+  `account2Address balance: ${Mina.getBalance(account2Address)} MINA`
+);
+
+console.log('----------MINA sending (with proof)----------');
+tx = await Local.transaction(feePayer, () => {
+  let party = Party.createSigned(zkappKey);
+  party.send({ to: account2Address, amount: UInt64.from(1_000_000) });
+  zkapp.account.nonce.assertEquals(zkapp.account.nonce.get().add(1));
+});
+await tx.prove();
+tx.send();
+
+console.log(`zkApp balance: ${Mina.getBalance(zkappAddress)} MINA`);
+console.log(
+  `account1Address balance: ${Mina.getBalance(account1Address)} MINA`
+);
+console.log(
+  `account2Address balance: ${Mina.getBalance(account2Address)} MINA`
+);
+
+shutdown();

src/lib/party.ts

@@ -50,6 +50,7 @@ export {
   Token,
   CallForest,
   createChildParty,
+  SendParams,
 };
 
 const ZkappStateLength = 8;
@@ -670,6 +671,24 @@ class Party implements Types.Party {
     };
   }
 
+  send({ to, amount }: Omit<SendParams, 'from'>) {
+    let party = this;
+    let receiverParty = createChildParty(party, to, {
+      tokenId: party.body.tokenId,
+      caller: party.body.tokenId,
+    });
+
+    // Sub the amount from the sender's account
+    let i0 = party.body.balanceChange;
+    party.body.balanceChange = new Int64(i0.magnitude, i0.sgn).sub(amount);
+
+    // Add the amount to send to the receiver's account
+    let i1 = receiverParty.body.balanceChange;
+    receiverParty.body.balanceChange = new Int64(i1.magnitude, i1.sgn).add(
+      amount
+    );
+  }
+
   get balance() {
     let party = this;
 

src/lib/token.test.ts

@@ -65,7 +65,7 @@ class TokenContract extends SmartContract {
     });
   }
 
-  @method send(
+  @method sendTokens(
     senderAddress: PublicKey,
     receiverAddress: PublicKey,
     amount: UInt64
@@ -253,7 +253,7 @@ describe('Token', () => {
       (
         await Mina.transaction(feePayer, () => {
           Party.fundNewAccount(feePayer);
-          zkapp.send(tokenAccount1, tokenAccount2, UInt64.from(10_000));
+          zkapp.sendTokens(tokenAccount1, tokenAccount2, UInt64.from(10_000));
           zkapp.sign(zkappKey);
         })
       )
@@ -279,7 +279,7 @@ describe('Token', () => {
 
       let tx = (
         await Mina.transaction(feePayer, () => {
-          zkapp.send(tokenAccount1, tokenAccount2, UInt64.from(10_000));
+          zkapp.sendTokens(tokenAccount1, tokenAccount2, UInt64.from(10_000));
           zkapp.sign(zkappKey);
         })
       ).sign([tokenAccount1Key]);
@@ -300,7 +300,11 @@ describe('Token', () => {
 
       let tx = (
         await Mina.transaction(feePayer, () => {
-          zkapp.send(tokenAccount1, tokenAccount2, UInt64.from(100_000_000));
+          zkapp.sendTokens(
+            tokenAccount1,
+            tokenAccount2,
+            UInt64.from(100_000_000)
+          );
           zkapp.sign(zkappKey);
         })
       ).sign([tokenAccount1Key]);

src/lib/zkapp.ts

@@ -29,6 +29,7 @@ import {
   Authorization,
   CallForest,
   getDefaultTokenId,
+  SendParams,
 } from './party';
 import { PrivateKey, PublicKey } from './signature';
 import * as Mina from './mina';
@@ -562,6 +563,10 @@ class SmartContract {
     return this.self.token();
   }
 
+  send(args: Omit<SendParams, 'from'>) {
+    return this.self.send(args);
+  }
+
   get tokenId() {
     return this.self.tokenId;
   }