Merge pull request #58 from gorbak25/fix-fetching

Refetch data on transient network failures

Author: zachleat

src/RemoteAssetCache.js

@@ -113,13 +113,14 @@ class RemoteAssetCache extends AssetCache {
 			throw new Error("Missing `#queue` instance.");
 		}
 
-		if(this.#queuePromise) {
-			return this.#queuePromise;
+		if(!this.#queuePromise) {
+			// optionsOverride not supported on fetch here for re-use
+			this.#queuePromise = this.#queue.add(() => this.fetch()).catch((e) => {
+				this.#queuePromise = undefined;
+				throw e;
+			});
 		}
 
-		// optionsOverride not supported on fetch here for re-use
-		this.#queuePromise = this.#queue.add(() => this.fetch());
-
 		return this.#queuePromise;
 	}
 
@@ -199,7 +200,7 @@ class RemoteAssetCache extends AssetCache {
 
 			return body;
 		} catch (e) {
-			if (this.cachedObject) {
+			if (this.cachedObject && this.getDurationMs(this.duration) > 0) {
 				debug(`Error fetching ${this.displayUrl}. Message: ${e.message}`);
 				debug(`Failing gracefully with an expired cache entry.`);
 				return super.getCachedValue();

test/QueueTest.js

@@ -216,3 +216,19 @@ test("Raw Fetch using fetch method (check parallel fetch promise reuse)", async
 		await ac2.destroy();
 	} catch (e) {}
 });
+
+test("Refetches data on transient failures", async (t) => {
+	let firstFetch = true;
+	let successData = "Good data";
+	let failData = "Transient error";
+	let ac1 = Fetch(() => {
+		if (firstFetch) {
+			firstFetch = false;
+			throw new Error(failData)
+		}
+		return successData;
+	}, {duration: "0s"})
+
+	await t.throwsAsync(async () => await ac1.queue())
+	t.is(await ac1.queue(), successData);
+})