network retries

Author: christianwwwwwwww

sdk/src/network-client.ts

@@ -1,4 +1,4 @@
-import { get, post, parseJSON, logAndThrow } from "./utils";
+import { get, post, parseJSON, logAndThrow, retryWithBackoff } from "./utils";
 import { Account } from "./account";
 import { BlockJSON } from "./models/blockJSON";
 import { TransactionJSON } from "./models/transaction/transactionJSON";
@@ -101,7 +101,7 @@ class AleoNetworkClient {
      */
     async fetchData<Type>(url = "/"): Promise<Type> {
         try {
-            return parseJSON(await this.fetchRaw(url));
+            return retryWithBackoff(() => this.fetchRaw(url).then(parseJSON));
         } catch (error) {
             throw new Error(`Error fetching data: ${error}`);
         }

sdk/src/utils.ts

@@ -39,3 +39,36 @@ export async function post(url: URL | string, options: RequestInit) {
 
     return response;
 }
+
+export async function retryWithBackoff<T>(
+    fn: () => Promise<T>,
+    maxAttempts = 5,
+    baseDelay = 100
+  ): Promise<T> {
+    for (let attempt = 1; attempt <= maxAttempts; attempt++) {
+      try {
+        return await fn();
+      } catch (err: any) {
+        const error = err as Error & { code?: string };
+        const isLast = attempt === maxAttempts;
+  
+        // retry only for certain errors
+        const retryable =
+        //   err?. 404s but that will probably not be 404 soon ? 
+          error?.message?.includes('404') ||
+        //   retry for timeouts as well
+          error?.message?.includes('5');
+  
+        if (!retryable || isLast) throw error;
+  
+        const jitter = Math.floor(Math.random() * baseDelay);
+        const delay = baseDelay * 2 ** (attempt - 1) + jitter;
+        console.warn(`Retry ${attempt}/${maxAttempts} failed. Retrying in ${delay}ms...`);
+  
+        await new Promise(res => setTimeout(res, delay));
+      }
+    }
+  
+    throw new Error("retryWithBackoff: unreachable");
+  }
+  

sdk/tests/network-client.test.ts

@@ -214,6 +214,29 @@ describe("NodeConnection", () => {
         });
     });
 
+    describe("retryWithBackoff", () => {
+        it("should retry failed network requests and eventually give up", async () => {
+          const client = new AleoNetworkClient("http://localhost:1234");
+      
+          let attemptCount = 0;
+      
+          client.fetchRaw = async () => {
+            attemptCount++;
+            console.warn(`fake fetchRaw attempt ${attemptCount}`);
+            throw new Error("503 Service Unavailable");
+          };
+      
+          try {
+            await client.fetchData("/block/latest");
+            throw new Error("Expected fetchData to fail");
+          } catch (err: any) {
+            expect(err.message).to.include("503");
+            expect(attemptCount).to.be.greaterThan(1);
+          }
+        });
+      });
+      
+
     describe("waitForTransactionConfirmation", () => {
         const mainnetAcceptedTx =
             "at1dl9lze8wscct0dee8x9tjnfmpjvj33hh23jcnp5f0ywjn5552yrsperzl9";