Add sample to demonstrate TimeToLive property usage (Azure#127)

* Add sample to demonstrate TimeToLive property usage

Issue Azure#125

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examples/samples/timeToLive.ts

@@ -0,0 +1,90 @@
+import {
+  delay,
+  OnMessage,
+  OnError,
+  MessagingError,
+  ServiceBusMessage,
+  ReceiveMode,
+  Namespace,
+  SendableMessageInfo,
+  generateUuid
+} from "../../lib";
+import * as dotenv from "dotenv";
+dotenv.config();
+
+const str = process.env.SERVICEBUS_CONNECTION_STRING || "";
+const queuePath = process.env.QUEUE_NAME || "";
+const deadLetterQueuePath = Namespace.getDeadLetterQueuePathForQueue(queuePath);
+const receiveClientTimeoutInMilliseconds = 10000;
+console.log("str: ", str);
+console.log("queue path: ", queuePath);
+console.log("deadletter queue path: ", deadLetterQueuePath);
+
+let ns: Namespace;
+
+/*
+  This sample demonstrates how TimeToLive property works. For more information, refer to
+  https://docs.microsoft.com/en-us/azure/service-bus-messaging/message-expiration
+*/
+async function main(): Promise<void> {
+  ns = Namespace.createFromConnectionString(str);
+  // Send messages with TTL property assigned
+  await sendMessage();
+
+  // Expire the messages by waiting for 40 seconds
+  await delay(40000);
+
+  // Attempt to receive message from main queue
+  // This will not show the message details that was sent, implying message got expired and removed
+  await receiveMessageFromQueue(queuePath);
+
+  // Attempt to receive message from DLQ
+  // This will contain the message details that was sent, implying the message is moved to DLQ
+  await receiveMessageFromQueue(deadLetterQueuePath);
+
+  console.log("\n>>>> Calling close....");
+  await ns.close();
+  console.log("\n>>>> sample Done!!!!");
+}
+
+async function sendMessage(): Promise<void> {
+  const recipeData = { name: "Limited Pineapple Icecream", type: "Dessert" };
+  const client = ns.createQueueClient(queuePath);
+  const messageBody = recipeData;
+  const message: SendableMessageInfo = {
+    body: messageBody,
+    contentType: "application/json",
+    label: "Recipe",
+    timeToLive: 30 * 1000, // 30 seconds
+    messageId: generateUuid()
+  };
+  await client.send(message);
+  console.log(">>>>> Sent message with data", recipeData);
+  await client.close();
+}
+
+async function receiveMessageFromQueue(givenQueuePath: string): Promise<void> {
+  const client = ns.createQueueClient(givenQueuePath, { receiveMode: ReceiveMode.peekLock });
+
+  const onMessageHandler: OnMessage = async (brokeredMessage: ServiceBusMessage) => {
+    console.log(">>>>> Received message with data", brokeredMessage.body);
+    await brokeredMessage.complete();
+  };
+
+  const onError: OnError = (err: MessagingError | Error) => {
+    console.log(">>>>> Error occurred: ", err);
+  };
+
+  console.log("\n>>>>> Receiving message from queue", givenQueuePath);
+  const receiverHandler = await client.receive(onMessageHandler, onError, { autoComplete: false });
+  await delay(receiveClientTimeoutInMilliseconds);
+  await receiverHandler.stop();
+  console.log(">>>>> Done receiving message from queue", givenQueuePath);
+
+  await client.close();
+}
+
+main().catch((err) => {
+  console.log(">>>>> Error occurred: ", err);
+  ns.close();
+});