From 96e493372002dd44998ac2be06c7249b7c2ea05e Mon Sep 17 00:00:00 2001
From: Daniel Bankhead <danielbankhead@google.com>
Date: Sun, 31 Oct 2021 19:26:57 -0700
Subject: [PATCH] feat: Add retry support for 504 (Gateway Timeout)

Fixes a downstream issue https://github.com/googleapis/nodejs-storage/issues/1635 by adding support for gateway timeouts - which is also compliant with https://cloud.google.com/storage/docs/retry-strategy#idempotency-operations
---
 src/util.ts  | 2 +-
 test/util.ts | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/util.ts b/src/util.ts
index 88f756bf..b83e5b48 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -544,7 +544,7 @@ export class Util {
    */
   shouldRetryRequest(err?: ApiError) {
     if (err) {
-      if ([408, 429, 500, 502, 503].indexOf(err.code!) !== -1) {
+      if ([408, 429, 500, 502, 503, 504].indexOf(err.code!) !== -1) {
         return true;
       }
 
diff --git a/test/util.ts b/test/util.ts
index 0d16f944..fb265259 100644
--- a/test/util.ts
+++ b/test/util.ts
@@ -1204,6 +1204,12 @@ describe('common/util', () => {
       assert.strictEqual(util.shouldRetryRequest(error), true);
     });
 
+    it('should return true with error code 504', () => {
+      const error = new ApiError('504');
+      error.code = 504;
+      assert.strictEqual(util.shouldRetryRequest(error), true);
+    });
+
     it('should detect rateLimitExceeded reason', () => {
       const rateLimitError = new ApiError('Rate limit error without code.');
       rateLimitError.errors = [{reason: 'rateLimitExceeded'}];