From ee4e6b32549e645da2750f69e848646854375549 Mon Sep 17 00:00:00 2001
From: Adam Weidman <adamfweidman@google.com>
Date: Wed, 13 May 2026 14:36:51 -0400
Subject: [PATCH] refactor(core): extract backoff delay helper in retry.ts

Extracts the duplicated delay and backoff logic in retryWithBackoff into a helper function applyBackoffDelay to improve maintainability.

TAG=agy

CONV=37b3cdb6-8437-4ced-ae4e-3d04054bacb1
---
 packages/core/src/utils/retry.ts | 35 +++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/packages/core/src/utils/retry.ts b/packages/core/src/utils/retry.ts
index 5740162fd6..d726d96be5 100644
--- a/packages/core/src/utils/retry.ts
+++ b/packages/core/src/utils/retry.ts
@@ -307,8 +307,7 @@ export async function retryWithBackoff<T>(
       ) {
         if (onPersistent429) {
           try {
-            const currentContext = getAvailabilityContext?.();
-            const currentModel = currentContext?.policy.model;
+            const currentModel = getAvailabilityContext?.()?.policy.model;
 
             const fallbackModel = await onPersistent429(
               authType,
@@ -326,10 +325,11 @@ export async function retryWithBackoff<T>(
                 continue;
               } else {
                 // If it's the same model (or a boolean retry signal), wait before retrying
-                const jitter = currentDelay * 0.3 * (Math.random() * 2 - 1);
-                const delayWithJitter = Math.max(0, currentDelay + jitter);
-                await delay(delayWithJitter, signal);
-                currentDelay = Math.min(maxDelayMs, currentDelay * 2);
+                currentDelay = await applyBackoffDelay(
+                  currentDelay,
+                  maxDelayMs,
+                  signal,
+                );
                 continue;
               }
             }
@@ -373,8 +373,7 @@ export async function retryWithBackoff<T>(
           );
           if (onPersistent429) {
             try {
-              const currentContext = getAvailabilityContext?.();
-              const currentModel = currentContext?.policy.model;
+              const currentModel = getAvailabilityContext?.()?.policy.model;
 
               const fallbackModel = await onPersistent429(
                 authType,
@@ -392,10 +391,11 @@ export async function retryWithBackoff<T>(
                   continue;
                 } else {
                   // If it's the same model (or a boolean retry signal), wait before retrying
-                  const jitter = currentDelay * 0.3 * (Math.random() * 2 - 1);
-                  const delayWithJitter = Math.max(0, currentDelay + jitter);
-                  await delay(delayWithJitter, signal);
-                  currentDelay = Math.min(maxDelayMs, currentDelay * 2);
+                  currentDelay = await applyBackoffDelay(
+                    currentDelay,
+                    maxDelayMs,
+                    signal,
+                  );
                   continue;
                 }
               }
@@ -506,3 +506,14 @@ function logRetryAttempt(
     debugLogger.warn(message, error); // Default to warn if error type is unknown
   }
 }
+
+async function applyBackoffDelay(
+  currentDelay: number,
+  maxDelayMs: number,
+  signal?: AbortSignal,
+): Promise<number> {
+  const jitter = currentDelay * 0.3 * (Math.random() * 2 - 1);
+  const delayWithJitter = Math.max(0, currentDelay + jitter);
+  await delay(delayWithJitter, signal);
+  return Math.min(maxDelayMs, currentDelay * 2);
+}