fix(WaitForProcessing): Shutdown option WaitForProcessing never entered on subscription close

src/lease-manager.ts

@@ -106,6 +106,8 @@ export class LeaseManager extends EventEmitter {
    * Adds a message to the inventory, kicking off the deadline extender if it
    * isn't already running.
    *
+   * @fires LeaseManager#full
+   *
    * @param {Message} message The message.
    * @private
    */
@@ -141,6 +143,10 @@ export class LeaseManager extends EventEmitter {
   }
   /**
    * Removes ALL messages from inventory, and returns the ones removed.
+   *
+   * @fires LeaseManager#free
+   * @fires LeaseManager#empty
+   *
    * @private
    */
   clear(): Message[] {
@@ -197,6 +203,7 @@ export class LeaseManager extends EventEmitter {
    * messages are left over.
    *
    * @fires LeaseManager#free
+   * @fires LeaseManager#empty
    *
    * @param {Message} message The message to remove.
    * @private

src/subscriber.ts

@@ -655,7 +655,7 @@ export class Message implements tracing.MessageWithAttributes {
  *     close() function.
  * @property {SubscriberCloseBehavior} [options.behavior] The behavior of the close operation.
  *     - NackImmediately: Sends nacks for all messages held by the client library, and
- *       wait for them to send.
+ *       wait for them to send. (default to match old behavior)
  *     - WaitForProcessing: Continues normal ack/nack and leasing processes until close
  *       to the timeout, then switches to NackImmediately behavior to close down.
  *     Use {@link SubscriberCloseBehaviors} for enum values.
@@ -970,9 +970,10 @@ export class Subscriber extends EventEmitter {
 
     const options = this._options.closeOptions;
 
-    // If no behavior is specified, default to Wait.
+    // If no behavior is specified, default to Nack. This most closely matches
+    // the old behavior.
     const behavior =
-      options?.behavior ?? SubscriberCloseBehaviors.WaitForProcessing;
+      options?.behavior ?? SubscriberCloseBehaviors.NackImmediately;
 
     // The timeout can't realistically be longer than the longest time we're willing
     // to lease messages.
@@ -1000,7 +1001,7 @@ export class Subscriber extends EventEmitter {
     const shutdownStart = Date.now();
     if (
       behavior === SubscriberCloseBehaviors.WaitForProcessing &&
-      !this._inventory.isEmpty
+      !this._inventory.isEmpty()
     ) {
       const waitTimeout = timeout.subtract(FINAL_NACK_TIMEOUT);
 

test/subscriber.ts

@@ -106,7 +106,7 @@ class FakeLeaseManager extends EventEmitter {
   remove(message: s.Message): void {}
 
   _isEmpty = true;
-  get isEmpty() {
+  isEmpty(): boolean {
     return this._isEmpty;
   }
 }