6871: Fixed bugs in releaseLoader

Author: tuj

assets/shared/release-loader.js

@@ -11,41 +11,48 @@ let activePromise = null;
 
 const ReleaseLoader = {
   async loadRelease() {
-    if (activePromise) {
+    if (activePromise !== null) {
       return activePromise;
     }
 
-    activePromise = new Promise((resolve, reject) => {
-      const nowTimestamp = new Date().getTime();
-
-      if (latestFetchTimestamp + configFetchInterval >= nowTimestamp) {
-        resolve(releaseData);
-      } else {
-        fetch(`/release.json?t=${nowTimestamp}`)
-          .then((response) => response.json())
-          .then((data) => {
-            latestFetchTimestamp = nowTimestamp;
-            releaseData = data;
-            resolve(releaseData);
-          })
-          .catch((err) => {
-            if (releaseData !== null) {
-              resolve(releaseData);
-            } else {
-              /* eslint-disable-next-line no-console */
-              console.warn("Could not find release.json. Returning defaults.");
-
-              return {
-                releaseTimestamp: null,
-                releaseVersion: null,
-              };
-            }
-          })
-          .finally(() => {
-            activePromise = null;
-          });
-      }
-    });
+    const nowTimestamp = new Date().getTime();
+
+    // Return early without going through activePromise so the caller always
+    // receives a real promise, not null.
+    if (latestFetchTimestamp + configFetchInterval >= nowTimestamp) {
+      return Promise.resolve(releaseData);
+    }
+
+    activePromise = fetch(`/release.json?t=${nowTimestamp}`)
+      .then((response) => response.json())
+      .then((data) => {
+        latestFetchTimestamp = nowTimestamp;
+        releaseData = data;
+        return releaseData;
+      })
+      .catch(() => {
+        if (releaseData !== null) {
+          // Bug 3 fix: advance the timestamp so the next call uses the
+          // cache instead of immediately retrying after a failed fetch.
+          latestFetchTimestamp = nowTimestamp;
+          return releaseData;
+        }
+
+        /* eslint-disable-next-line no-console */
+        console.warn("Could not find release.json. Returning defaults.");
+
+        // Return defaults.
+        return {
+          releaseTime: null,
+          releaseTimestamp: null,
+          releaseVersion: null,
+        };
+      })
+      .finally(() => {
+        // Always clear activePromise via finally so concurrent callers share a
+        // single in-flight fetch and it is cleared on both success and failure.
+        activePromise = null;
+      });
 
     return activePromise;
   },