Make slow RPC ack threshold configurable in tests

- Add a test-only setter for the slow RPC ack timer
- Use a shorter threshold in wsTransport coverage to keep the test fast

Author: juliusmarminge

apps/web/src/rpc/requestLatencyState.ts

@@ -5,6 +5,7 @@ import { appAtomRegistry } from "./atomRegistry";
 
 export const SLOW_RPC_ACK_THRESHOLD_MS = 15_000;
 export const MAX_TRACKED_RPC_ACK_REQUESTS = 256;
+let slowRpcAckThresholdMs = SLOW_RPC_ACK_THRESHOLD_MS;
 
 export interface SlowRpcAckRequest {
   readonly requestId: string;
@@ -56,12 +57,12 @@ export function trackRpcRequestSent(requestId: string, tag: string): void {
     startedAt: new Date(startedAtMs).toISOString(),
     startedAtMs,
     tag,
-    thresholdMs: SLOW_RPC_ACK_THRESHOLD_MS,
+    thresholdMs: slowRpcAckThresholdMs,
   };
   const timeoutId = setTimeout(() => {
     pendingRpcAckRequests.delete(requestId);
     appendSlowRpcAckRequest(request);
-  }, SLOW_RPC_ACK_THRESHOLD_MS);
+  }, slowRpcAckThresholdMs);
 
   pendingRpcAckRequests.set(requestId, {
     request,
@@ -119,9 +120,14 @@ function evictOldestPendingRpcRequestIfNeeded(): void {
 }
 
 export function resetRequestLatencyStateForTests(): void {
+  slowRpcAckThresholdMs = SLOW_RPC_ACK_THRESHOLD_MS;
   clearAllTrackedRpcRequests();
 }
 
+export function setSlowRpcAckThresholdMsForTests(thresholdMs: number): void {
+  slowRpcAckThresholdMs = thresholdMs;
+}
+
 export function useSlowRpcAckRequests(): ReadonlyArray<SlowRpcAckRequest> {
   return useAtomValue(slowRpcAckRequestsAtom);
 }

apps/web/src/wsTransport.test.ts

@@ -5,7 +5,11 @@ import {
   __resetClientTracingForTests,
   configureClientTracing,
 } from "./observability/clientTracing";
-import { getSlowRpcAckRequests, resetRequestLatencyStateForTests } from "./rpc/requestLatencyState";
+import {
+  getSlowRpcAckRequests,
+  resetRequestLatencyStateForTests,
+  setSlowRpcAckThresholdMsForTests,
+} from "./rpc/requestLatencyState";
 import {
   getWsConnectionStatus,
   getWsConnectionUiState,
@@ -292,6 +296,8 @@ describe("WsTransport", () => {
   });
 
   it("marks unary requests as slow until the first server ack arrives", async () => {
+    const slowAckThresholdMs = 25;
+    setSlowRpcAckThresholdMsForTests(slowAckThresholdMs);
     const transport = new WsTransport("ws://localhost:3020");
 
     const requestPromise = transport.request((client) =>
@@ -320,7 +326,7 @@ describe("WsTransport", () => {
           tag: WS_METHODS.serverUpsertKeybinding,
         },
       ]);
-    }, 5_000);
+    }, 1_000);
 
     socket.serverMessage(
       JSON.stringify({
@@ -343,7 +349,7 @@ describe("WsTransport", () => {
     expect(getSlowRpcAckRequests()).toEqual([]);
 
     await transport.dispose();
-  }, 10_000);
+  }, 5_000);
 
   it("sends unary RPC requests and resolves successful exits", async () => {
     const transport = new WsTransport("ws://localhost:3020");