Add example on how to generate transaction IDs on demand and scenarios

examples/generate-txid-on-demand.js

@@ -0,0 +1,169 @@
+import {
+    AccountId,
+    PrivateKey,
+    Client,
+    Hbar,
+    Timestamp,
+    TransactionId,
+    AccountCreateTransaction,
+    TransferTransaction,
+} from "@hashgraph/sdk";
+
+import dotenv from "dotenv";
+dotenv.config();
+
+/*
+Examples that demonstrates the use of generating transaction IDs on demand
+
+## Example 1:
+Sometimes, when you are trying to execute transactions `asynchronosly`,
+there is a tiny bit of chance to generate the same `transactionId` given the same `accountId`
+and the current timestamp.
+
+With the following approach to generate custom `transactionId`, this issue is avoided
+
+### Steps
+1. Create an account to whom to send tinybars
+2. Make a thousand iterations of transfer transactions with custom generated `transactionId`
+3. Await the receipts of every transaction
+4. Check if the count of receipts with status `SUCCESS` equals the count of transactions (should be 1000)
+
+
+## Example 2:
+The `TransactionId` object contains the valid start time for the transaction. This means that
+by setting the valid start time to a moment in the future, you would be able to execute the transaction
+after the set period (in seconds)
+
+1. Create custom `transactionId` with valid start 10 seconds after the current time
+2. Wait 15 seconds in order for the transaction to be valid and then submit it
+*/
+
+async function main() {
+    if (process.env.OPERATOR_ID == null || process.env.OPERATOR_KEY == null) {
+        throw new Error(
+            "Environment variables OPERATOR_ID, and OPERATOR_KEY are required."
+        );
+    }
+    const operatorId = AccountId.fromString(process.env.OPERATOR_ID);
+    const operatorKey = PrivateKey.fromString(process.env.OPERATOR_KEY);
+
+    const client = Client.forTestnet().setOperator(operatorId, operatorKey);
+
+    /**
+     *     Example 1
+     *
+     * Step 1
+     *
+     * Create an account to whom to send tinybars
+     */
+    const newKey = PrivateKey.generate();
+
+    console.log(`New account private key: ${newKey.toString()}`);
+    console.log(`New account public key: ${newKey.publicKey.toString()}`);
+
+    const accountCreateTx = await new AccountCreateTransaction()
+        .setInitialBalance(new Hbar(10)) // 10 h
+        .setKey(newKey.publicKey)
+        .freezeWith(client)
+        .execute(client);
+
+    const newAccountId = (
+        await accountCreateTx.getReceipt(client)
+    ).accountId.toString();
+    console.log(`New account id: ${newAccountId}`);
+
+    /**
+     * Step 2
+     *
+     * Make a thousand iterations of transfer transactions
+     * with custom generated `transactionId`
+     */
+    const transactionsCount = 1000;
+    let transactions = [];
+    let nanosOffset = 1000000;
+    for (let i = 0; i < transactionsCount; i++) {
+        const seconds = Math.round(Date.now() / 1000);
+        const validStart = new Timestamp(seconds, nanosOffset);
+        nanosOffset += 10000;
+
+        const transactionId = TransactionId.withValidStart(
+            operatorId,
+            validStart
+        );
+
+        const transferHbar = new TransferTransaction()
+            .setTransactionId(transactionId)
+            .addHbarTransfer(operatorId, Hbar.fromTinybars(-1))
+            .addHbarTransfer(newAccountId, Hbar.fromTinybars(1));
+
+        transactions.push(transferHbar.execute(client));
+    }
+    const responsesResult = await Promise.all(transactions);
+
+    /**
+     * Step 3
+     *
+     * Await the receipts of every transaction
+     */
+    let count = 0;
+    let receipts = [];
+    for (let i = 0; i < responsesResult.length; i++) {
+        receipts.push(responsesResult[i].getReceipt(client));
+    }
+    const receiptsResult = await Promise.all(receipts);
+
+    /**
+     * Step 4
+     *
+     * Check if the count of receipts with status `SUCCESS` equals the count of transactions (should be 1000)
+     */
+    receiptsResult.forEach((receipt) =>
+        receipt.status.toString() == "SUCCESS"
+            ? count++
+            : console.log(`Failed with: ${receipt.status.toString()}`)
+    );
+    transactionsCount == count
+        ? console.log(`All transactions are executed successfully`)
+        : console.log(`${transactionsCount - count} unsuccessful transactions`);
+
+    /**
+     *     Example 2
+     *
+     * Step 1
+     *
+     * Create custom `transactionId` with valid start 10 seconds after the current time
+     */
+    const nowInSeconds = Math.floor(Date.now() / 1000);
+    const secondsDelay = 10;
+    const seconds = nowInSeconds + secondsDelay;
+    const validStart = new Timestamp(seconds, 0);
+    const transactionId = TransactionId.withValidStart(operatorId, validStart);
+
+    /**
+     * Step 2
+     *
+     * Wait 15 seconds in order for the transaction to be valid and then submit it
+     */
+    await wait(15000);
+
+    const transferHbar = await new TransferTransaction()
+        .setTransactionId(transactionId)
+        .addHbarTransfer(operatorId, Hbar.fromTinybars(-1))
+        .addHbarTransfer(newAccountId, Hbar.fromTinybars(1))
+        .execute(client);
+
+    const status = (await transferHbar.getReceipt(client)).status.toString();
+    console.log(status);
+}
+
+/**
+ * @param {number} timeout
+ * @returns {Promise<any>}
+ */
+function wait(timeout) {
+    return new Promise((resolve) => {
+        setTimeout(resolve, timeout);
+    });
+}
+
+void main();