fix(service-worker): prevent duplicate fetches during concurrent update checks (#61443)

arturovt · kirjs · commit b93fa22f2509 · 2025-06-03T15:57:30.000-04:00
Previously, multiple simultaneous calls to `checkForUpdate()` could result in redundant fetches and hashing of the update manifest, leading to unnecessary network and CPU usage. This change introduces a mechanism to track an in-progress update check using a cached promise (`ongoingCheckForUpdate`). Subsequent calls to `checkForUpdate()` while a check is in progress will return the same promise instead of triggering a new request. Once the check completes (successfully or not), the cached promise is cleared, allowing future update checks to proceed normally. This improves efficiency and prevents overlapping update logic in applications that may invoke `checkForUpdate()` from multiple sources (e.g. polling, manual triggers). PR Close #61443
diff --git a/packages/service-worker/src/update.ts b/packages/service-worker/src/update.ts
@@ -53,6 +53,8 @@ export class SwUpdate {
     return this.sw.isEnabled;
   }
 
+  private ongoingCheckForUpdate: Promise<boolean> | null = null;
+
   constructor(private sw: NgswCommChannel) {
     if (!sw.isEnabled) {
       this.versionUpdates = NEVER;
@@ -81,8 +83,16 @@ export class SwUpdate {
     if (!this.sw.isEnabled) {
       return Promise.reject(new Error(ERR_SW_NOT_SUPPORTED));
     }
+    if (this.ongoingCheckForUpdate) {
+      return this.ongoingCheckForUpdate;
+    }
     const nonce = this.sw.generateNonce();
-    return this.sw.postMessageWithOperation('CHECK_FOR_UPDATES', {nonce}, nonce);
+    this.ongoingCheckForUpdate = this.sw
+      .postMessageWithOperation('CHECK_FOR_UPDATES', {nonce}, nonce)
+      .finally(() => {
+        this.ongoingCheckForUpdate = null;
+      });
+    return this.ongoingCheckForUpdate;
   }
 
   /**
