caching

src/widgets/feed/proxy.js

@@ -1,3 +1,5 @@
+import cache from "memory-cache";
+
 import { parseFeed } from "./utils";
 
 import getServiceWidget from "utils/config/service-helpers";
@@ -6,6 +8,7 @@ import { sanitizeErrorURL } from "utils/proxy/api-helpers";
 import { httpProxy } from "utils/proxy/http";
 
 const logger = createLogger("feedProxyHandler");
+const CACHE_MS = 10 * 60 * 1000;
 
 export default async function feedProxyHandler(req, res) {
   const { group, service, index } = req.query;
@@ -22,24 +25,31 @@ export default async function feedProxyHandler(req, res) {
     return res.status(400).json({ error: "Invalid feed URL" });
   }
 
-  const [status, , data] = await httpProxy(url, {
-    headers: {
-      "User-Agent": `gethomepage/${process.env.NEXT_PUBLIC_VERSION || "dev"}`,
-      Accept: "application/rss+xml, application/atom+xml, application/xml;q=0.9, text/xml;q=0.9, */*;q=0.8",
-    },
-  });
+  const cacheKey = `feed:${url.href}`;
+  let items = cache.get(cacheKey);
 
-  if (status !== 200) {
-    logger.debug("HTTP %d retrieving feed %s//%s%s", status, url.protocol, url.host, url.pathname);
-    return res.status(status).json({ error: { message: "HTTP Error", url: sanitizeErrorURL(url) } });
-  }
+  if (!items) {
+    const [status, , data] = await httpProxy(url, {
+      headers: {
+        "User-Agent": `gethomepage/${process.env.NEXT_PUBLIC_VERSION || "dev"}`,
+        Accept: "application/rss+xml, application/atom+xml, application/xml;q=0.9, text/xml;q=0.9, */*;q=0.8",
+      },
+    });
 
-  let items;
-  try {
-    items = parseFeed(Buffer.from(data).toString(), url.href);
-  } catch (e) {
-    logger.debug("Error parsing feed %s//%s%s: %s", url.protocol, url.host, url.pathname, e.message);
-    return res.status(500).json({ error: { message: "Invalid feed", url: sanitizeErrorURL(url) } });
+    if (status !== 200) {
+      logger.debug("HTTP %d retrieving feed %s//%s%s", status, url.protocol, url.host, url.pathname);
+      return res.status(status).json({ error: { message: "HTTP Error", url: sanitizeErrorURL(url) } });
+    }
+
+    try {
+      items = parseFeed(Buffer.from(data).toString(), url.href);
+    } catch (e) {
+      logger.debug("Error parsing feed %s//%s%s: %s", url.protocol, url.host, url.pathname, e.message);
+      return res.status(500).json({ error: { message: "Invalid feed", url: sanitizeErrorURL(url) } });
+    }
+
+    // only successful fetches are cached
+    cache.put(cacheKey, items, CACHE_MS);
   }
 
   const maxItems = parseInt(widget.maxItems, 10) || 5;

src/widgets/feed/proxy.test.js

@@ -1,3 +1,4 @@
+import cache from "memory-cache";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 
 import createMockRes from "test-utils/create-mock-res";
@@ -36,6 +37,7 @@ const req = { query: { group: "g", service: "svc", index: "0" } };
 describe("widgets/feed/proxy", () => {
   beforeEach(() => {
     vi.clearAllMocks();
+    cache.clear();
   });
 
   it("returns 400 when the url is missing or invalid", async () => {
@@ -110,4 +112,37 @@ describe("widgets/feed/proxy", () => {
     expect(res.statusCode).toBe(500);
     expect(res.body).toEqual({ error: { message: "Invalid feed", url: "example.com (see logs for details)" } });
   });
+
+  it("shares one cached fetch across widgets with different options", async () => {
+    getServiceWidget
+      .mockResolvedValueOnce({ type: "feed", url: "https://example.com/feed.xml", maxItems: 1 })
+      .mockResolvedValueOnce({ type: "feed", url: "https://example.com/feed.xml", images: false });
+    httpProxy.mockResolvedValue([200, "application/rss+xml", Buffer.from(feed)]);
+
+    const first = createMockRes();
+    await feedProxyHandler(req, first);
+    const second = createMockRes();
+    await feedProxyHandler(req, second);
+
+    expect(httpProxy).toHaveBeenCalledTimes(1);
+    expect(first.body.items).toHaveLength(1);
+    expect(second.body.items).toHaveLength(5);
+    expect(second.body.items[0].image).toBeUndefined();
+  });
+
+  it("does not cache failures", async () => {
+    getServiceWidget.mockResolvedValue({ type: "feed", url: "https://example.com/feed.xml" });
+    httpProxy
+      .mockResolvedValueOnce([404, "text/html", Buffer.from("Not found")])
+      .mockResolvedValueOnce([200, "application/rss+xml", Buffer.from(feed)]);
+
+    const failed = createMockRes();
+    await feedProxyHandler(req, failed);
+    const recovered = createMockRes();
+    await feedProxyHandler(req, recovered);
+
+    expect(failed.statusCode).toBe(404);
+    expect(recovered.statusCode).toBe(200);
+    expect(httpProxy).toHaveBeenCalledTimes(2);
+  });
 });