fix: example budget programs

web3.js/examples/budget-common.js

@@ -0,0 +1,67 @@
+/* eslint-disable import/no-commonjs */
+
+/*
+  Common code for the budget program examples
+*/
+
+function getTransactionFee(connection) {
+  return connection.getRecentBlockhash().then(response => {
+    return response[1];
+  });
+}
+
+function showBalance(connection, account1, account2, contractState) {
+  console.log(`\n== Account State`);
+  return Promise.all([
+    connection.getBalance(account1.publicKey),
+    connection.getBalance(account2.publicKey),
+    connection.getBalance(contractState.publicKey),
+  ]).then(([fromBalance, toBalance, contractStateBalance]) => {
+    console.log(
+      `Account1:       ${account1.publicKey} has a balance of ${fromBalance}`,
+    );
+    console.log(
+      `Account2:       ${account2.publicKey} has a balance of ${toBalance}`,
+    );
+    console.log(
+      `Contract State: ${contractState.publicKey} has a balance of ${contractStateBalance}`,
+    );
+  });
+}
+
+function confirmTransaction(connection, signature) {
+  console.log('Confirming transaction:', signature);
+  return connection.getSignatureStatus(signature).then(confirmation => {
+    if (confirmation && 'Ok' in confirmation) {
+      console.log('Transaction confirmed');
+    } else if (confirmation) {
+      throw new Error(
+        `Transaction was not confirmed (${JSON.stringify(confirmation.Err)})`,
+      );
+    } else {
+      throw new Error(`Transaction was not confirmed (${confirmation})`);
+    }
+  });
+}
+
+function airDrop(connection, account, feeCalculator) {
+  const airdrop = 100 + 5 * feeCalculator.targetLamportsPerSignature;
+  console.log(`\n== Requesting airdrop of ${airdrop} to ${account.publicKey}`);
+  return connection
+    .requestAirdrop(account.publicKey, airdrop)
+    .then(signature => confirmTransaction(connection, signature));
+}
+
+function sleep(millis) {
+  return new Promise(resolve => {
+    setTimeout(resolve, millis);
+  });
+}
+
+module.exports = {
+  airDrop,
+  confirmTransaction,
+  getTransactionFee,
+  showBalance,
+  sleep,
+};