Add tags route timeout

src/routes/tags.ts

@@ -3,10 +3,21 @@ import { z } from "zod";
 import { accessLog } from "../middleware/accessLog";
 import { logger } from "../config/logger";
 import { getMarketTags } from "../repositories/marketRepository";
+import { abortableRace, requestTimeout, RequestAbortedError } from "../middleware/timeout";
 
 export const tagsRouter = Router();
 tagsRouter.use(accessLog);
 
+const TAGS_TIMEOUT_MS = 5000;
+
+tagsRouter.use(
+  requestTimeout(TAGS_TIMEOUT_MS, {
+    statusCode: 504,
+    code: "gateway_timeout",
+    message: "Tags request timed out",
+  }),
+);
+
 const tagsQuerySchema = z.object({
   limit: z.coerce.number().int().min(1).max(100).default(10),
 });
@@ -16,7 +27,7 @@ const tagsQuerySchema = z.object({
  * /api/tags:
  *   get:
  *     summary: Retrieve system tags
- *     description: Returns a list of tags. Used to test the tags access log.
+ *     description: Returns a list of tags. Used to test the tags access log. The request is bounded by a per-request timeout and returns 504 if the backing read exceeds the deadline.
  *     tags:
  *       - Tags
  *     parameters:
@@ -46,9 +57,17 @@ const tagsQuerySchema = z.object({
  *           application/json:
  *             schema:
  *               $ref: '#/components/schemas/ErrorResponse'
+ *       504:
+ *         description: Tags lookup exceeded the per-request timeout
+ *         content:
+ *           application/json:
+ *             schema:
+ *               $ref: '#/components/schemas/ErrorResponse'
  */
 tagsRouter.get("/", async (req: Request, res: Response, next: NextFunction) => {
   const reqId = String((req as Request & { id?: unknown }).id ?? "anon");
+  const signal = res.locals.abortSignal as { aborted: boolean; addEventListener: (...args: unknown[]) => void; removeEventListener: (...args: unknown[]) => void } | undefined;
+
   try {
     const parsed = tagsQuerySchema.safeParse(req.query);
     if (!parsed.success) {
@@ -58,14 +77,22 @@ tagsRouter.get("/", async (req: Request, res: Response, next: NextFunction) => {
     const { limit } = parsed.data;
 
     logger.debug({ reqId, correlationId: reqId, limit }, "Fetching system tags");
-    
-    const data = await getMarketTags();
+
+    const data = await abortableRace(getMarketTags(), signal);
     const tags = data.map((d) => d.tag).slice(0, limit);
-    
+
     logger.info({ reqId, correlationId: reqId, count: tags.length }, "System tags fetched successfully");
-    
+
     res.json({ tags });
   } catch (e) {
+    if (e instanceof RequestAbortedError) {
+      logger.warn(
+        { correlationId: reqId, path: req.path },
+        "Abandoned /api/tags request after timeout",
+      );
+      return;
+    }
+
     logger.error({ reqId, correlationId: reqId, err: e }, "Failed to fetch system tags");
     next(e);
   }

tests/routes/tags.test.ts

@@ -5,6 +5,14 @@ import { closeAuthPool } from "../../src/middleware/requireAuth";
 import { getMarketTags } from "../../src/repositories/marketRepository";
 import { errorHandler } from "../../src/middleware/errorHandler";
 
+jest.mock("../../src/middleware/timeout", () => {
+  const actual = jest.requireActual("../../src/middleware/timeout");
+  return {
+    ...actual,
+    requestTimeout: actual.requestTimeout,
+  };
+});
+
 jest.mock("../../src/repositories/marketRepository");
 describe("Tags API", () => {
   let app: any;
@@ -18,6 +26,7 @@ describe("Tags API", () => {
 
   beforeEach(() => {
     jest.resetAllMocks();
+    jest.useRealTimers();
     (getMarketTags as jest.Mock).mockResolvedValue([
       { tag: "stellar", count: 10 },
       { tag: "wave", count: 5 },
@@ -70,4 +79,45 @@ describe("Tags API", () => {
       /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/,
     );
   });
+
+  it("should return 504 when tag lookup exceeds the timeout", async () => {
+    jest.useFakeTimers();
+    (getMarketTags as jest.Mock).mockImplementation(
+      () => new Promise((resolve) => setTimeout(() => resolve([{ tag: "slow", count: 1 }]), 6000)),
+    );
+
+    const responsePromise = request(app).get("/api/tags");
+    await jest.advanceTimersByTimeAsync(5000);
+    const res = await responsePromise;
+
+    expect(res.status).toBe(504);
+    expect(res.body.error).toMatchObject({
+      code: "gateway_timeout",
+      message: "Tags request timed out",
+      requestId: expect.any(String),
+    });
+  });
+
+  it("should abandon the handler result after timeout instead of sending a second response", async () => {
+    jest.useFakeTimers();
+
+    let resolveTags: ((value: Array<{ tag: string; count: number }>) => void) | undefined;
+    (getMarketTags as jest.Mock).mockImplementation(
+      () => new Promise((resolve) => {
+        resolveTags = resolve;
+      }),
+    );
+
+    const responsePromise = request(app).get("/api/tags");
+    await jest.advanceTimersByTimeAsync(5000);
+    const res = await responsePromise;
+
+    expect(res.status).toBe(504);
+
+    resolveTags?.([{ tag: "late", count: 1 }]);
+    await Promise.resolve();
+    await Promise.resolve();
+
+    expect(getMarketTags).toHaveBeenCalledTimes(1);
+  });
 });