Reduce Kathy Polling in V2 (#1357)

typescript/helloworld/src/app/app.ts

@@ -67,6 +67,12 @@ export class HelloWorldApp<
     return this.core.waitForMessageProcessing(receipt);
   }
 
+  async waitForMessageProcessed(
+    receipt: ethers.ContractReceipt,
+  ): Promise<void> {
+    return this.core.waitForMessageProcessed(receipt);
+  }
+
   async channelStats<From extends Chain>(
     from: From,
     to: Remotes<Chain, From>,

typescript/infra/scripts/helloworld/kathy.ts

@@ -413,7 +413,7 @@ async function sendMessage(
 
   try {
     await utils.timeout(
-      app.waitForMessageReceipt(receipt),
+      app.waitForMessageProcessed(receipt),
       messageReceiptTimeout,
       'Timeout waiting for message to be received',
     );

typescript/sdk/src/core/HyperlaneCore.ts

@@ -133,6 +133,20 @@ export class HyperlaneCore<
     });
   }
 
+  protected async waitForMessageWasProcessed(
+    message: DispatchedMessage,
+  ): Promise<void> {
+    const id = utils.messageId(message.message);
+    const { mailbox } = this.getDestination(message);
+    await utils.pollAsync(async () => {
+      const delivered = await mailbox.delivered(id);
+      if (!delivered) {
+        throw new Error(`Message ${id} not yet processed`);
+      }
+    });
+    return;
+  }
+
   getDispatchedMessages(sourceTx: ethers.ContractReceipt): DispatchedMessage[] {
     const mailbox = Mailbox__factory.createInterface();
     const dispatchLogs = sourceTx.logs
@@ -161,4 +175,13 @@ export class HyperlaneCore<
     const messages = this.getDispatchedMessages(sourceTx);
     return Promise.all(messages.map((msg) => this.waitForProcessReceipt(msg)));
   }
+
+  async waitForMessageProcessed(
+    sourceTx: ethers.ContractReceipt,
+  ): Promise<void> {
+    const messages = this.getDispatchedMessages(sourceTx);
+    await Promise.all(
+      messages.map((msg) => this.waitForMessageWasProcessed(msg)),
+    );
+  }
 }

typescript/utils/src/utils.ts

@@ -205,6 +205,26 @@ export async function retryAsync<T>(
   throw saveError;
 }
 
+export async function pollAsync<T>(
+  runner: () => Promise<T>,
+  delayMs = 500,
+  maxAttempts: number | undefined = undefined,
+) {
+  let attempts = 0;
+  let saveError;
+  while (!maxAttempts || attempts < maxAttempts) {
+    try {
+      const ret = await runner();
+      return ret;
+    } catch (error) {
+      saveError = error;
+      attempts += 1;
+      await sleep(delayMs);
+    }
+  }
+  throw saveError;
+}
+
 export function median(a: number[]): number {
   const sorted = a.slice().sort();
   const mid = Math.floor(sorted.length / 2);