Add budget example

web3.js/examples/budget.js

@@ -0,0 +1,113 @@
+/*
+  Example of using the Budget program to perform a time-lock payment of 50
+  tokens from account1 to account2.
+*/
+
+//eslint-disable-next-line import/no-commonjs
+const solanaWeb3 = require('..');
+//const solanaWeb3 = require('@solana/web3.js');
+
+const account1 = new solanaWeb3.Account();
+const account2 = new solanaWeb3.Account();
+const contractFunds = new solanaWeb3.Account();
+const contractState = new solanaWeb3.Account();
+
+let url;
+url = 'http://localhost:8899';
+//url = 'http://testnet.solana.com:8899';
+const connection = new solanaWeb3.Connection(url);
+
+function showBalance() {
+  console.log(`\n== Account State`);
+  return Promise.all([
+    connection.getBalance(account1.publicKey),
+    connection.getBalance(account2.publicKey),
+    connection.getBalance(contractFunds.publicKey),
+    connection.getBalance(contractState.publicKey),
+  ]).then(([fromBalance, toBalance, contractFundsBalance, contractStateBalance]) => {
+    console.log(`Account1:       ${account1.publicKey} has a balance of ${fromBalance}`);
+    console.log(`Account2:       ${account2.publicKey} has a balance of ${toBalance}`);
+    console.log(`Contract Funds: ${contractFunds.publicKey} has a balance of ${contractFundsBalance}`);
+    console.log(`Contract State: ${contractState.publicKey} has a balance of ${contractStateBalance}`);
+  });
+}
+
+function confirmTransaction(signature) {
+  console.log('Confirming transaction:', signature);
+  return connection.confirmTransaction(signature)
+  .then((confirmation) => {
+    if (!confirmation) {
+      throw new Error('Transaction was not confirmed');
+    }
+    console.log('Transaction confirmed');
+  });
+}
+
+function airDrop() {
+  console.log(`\n== Requesting airdrop of 100 to ${account1.publicKey}`);
+  return connection.requestAirdrop(account1.publicKey, 100)
+  .then(confirmTransaction);
+}
+
+showBalance()
+.then(airDrop)
+.then(showBalance)
+.then(() => {
+  console.log(`\n== Creating account for the contract funds`);
+  const transaction = solanaWeb3.SystemContract.createAccount(
+    account1.publicKey,
+    contractFunds.publicKey,
+    50, // number of tokens to transfer
+    0,
+    solanaWeb3.BudgetContract.contractId,
+  );
+  return connection.sendTransaction(account1, transaction);
+})
+.then(confirmTransaction)
+.then(showBalance)
+.then(() => {
+  console.log(`\n== Creating account for the contract state`);
+  const transaction = solanaWeb3.SystemContract.createAccount(
+    account1.publicKey,
+    contractState.publicKey,
+    1, // sender pays 1 token to hold the contract state
+    solanaWeb3.BudgetContract.space,
+    solanaWeb3.BudgetContract.contractId,
+  );
+  return connection.sendTransaction(account1, transaction);
+})
+.then(confirmTransaction)
+.then(showBalance)
+.then(() => {
+  console.log(`\n== Initializing contract`);
+  const transaction = solanaWeb3.BudgetContract.pay(
+    contractFunds.publicKey,
+    contractState.publicKey,
+    account2.publicKey,
+    50,
+    solanaWeb3.BudgetContract.timestampCondition(account1.publicKey, new Date("2050")),
+  );
+  return connection.sendTransaction(contractFunds, transaction);
+})
+.then(confirmTransaction)
+.then(showBalance)
+.then(() => {
+  console.log(`\n== Witness contract`);
+  const transaction = solanaWeb3.BudgetContract.applyTimestamp(
+    account1.publicKey,
+    contractState.publicKey,
+    account2.publicKey,
+    new Date("2050"),
+  );
+  return connection.sendTransaction(account1, transaction);
+})
+.then(confirmTransaction)
+.then(showBalance)
+
+.then(() => {
+  console.log('\nDone');
+})
+
+.catch((err) => {
+  console.log(err);
+});

web3.js/src/budget-contract.js

@@ -118,6 +118,14 @@ export class BudgetContract {
     return '4uQeVj5tqViQh7yWWGStvkEG1Zmhx6uasJtWCJziofM';
   }
 
+  /**
+   * The amount of space this contract requires
+   */
+  static get space(): number {
+    return 128;
+  }
+
+
   /**
    * Creates a timestamp condition
    */
@@ -196,7 +204,7 @@ export class BudgetContract {
 
       return new Transaction({
         fee: 0,
-        keys: [from, contract],
+        keys: [from, contract, to],
         contractId: this.contractId,
         userdata: userdata.slice(0, pos),
       });
@@ -217,7 +225,7 @@ export class BudgetContract {
 
       return new Transaction({
         fee: 0,
-        keys: [from, to],
+        keys: [from, contract, to],
         contractId: this.contractId,
         userdata: userdata.slice(0, pos),
       });

web3.js/src/index.js

@@ -2,3 +2,5 @@
 export {Account} from './account';
 export {Connection} from './connection';
 export {Transaction} from './transaction';
+export {SystemContract} from './system-contract';
+export {BudgetContract} from './budget-contract';