From 476cd05705b350e50ed715677e76773638774b62 Mon Sep 17 00:00:00 2001
From: Janghoon Lee <44862514+savagemanage@users.noreply.github.com>
Date: Mon, 21 Sep 2026 12:00:41 +0000
Subject: [PATCH] fix(test): scale the ACP subprocess waits for the slow
 platform too

A third Windows shard failed, and this one was not a spawn timeout: `stdin EOF
exits cleanly` gave a subprocess five seconds to exit and failed at 6.5s with a
bare `TimeoutError`. Windows process teardown is slower, and five seconds was
tight enough to flake.

Every wait in the ACP test client is on a subprocess round trip, so all three
bounds now go through the same scaler as the harness: the request wait, the
notification wait's default, and the explicit values callers pass to it.

This is the third place a fixed millisecond figure met a slower platform, after
the spawn timeout and the ready timeout. The pattern is the point -- a bound
written as a literal beside a subprocess is a bound that will eventually be too
small on somebody's machine, and `slowPlatform` is where that correction belongs
rather than in each number.
---
 packages/redrob/test/cli/acp/acp-test-client.ts | 9 +++++++--
 packages/redrob/test/cli/acp/lifecycle.test.ts  | 7 +++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/packages/redrob/test/cli/acp/acp-test-client.ts b/packages/redrob/test/cli/acp/acp-test-client.ts
index 1588d344d7..f8bd4ae2af 100644
--- a/packages/redrob/test/cli/acp/acp-test-client.ts
+++ b/packages/redrob/test/cli/acp/acp-test-client.ts
@@ -2,6 +2,7 @@ import { expect } from "bun:test"
 import type { SessionConfigOption, SessionConfigSelectOption } from "@agentclientprotocol/sdk"
 import { Duration, Effect } from "effect"
 import type { AcpHandle } from "../../lib/cli-process"
+import { slowPlatform } from "../../lib/cli-process"
 
 type JsonRpcRequest = {
   readonly jsonrpc: "2.0"
@@ -44,15 +45,19 @@ export function createAcpClient(acp: AcpHandle): AcpClient {
       yield* acp.send(message)
 
       while (true) {
-        const received = yield* acp.receive.pipe(Effect.timeout(Duration.seconds(15)))
+        const received = yield* acp.receive.pipe(Effect.timeout(Duration.millis(slowPlatform(15_000))))
         if (isJsonRpcResponse<T>(received) && received.id === id) return received
       }
     })
 
+  /*
+    The default is scaled for the slow platform, as are the explicit values callers pass -- every wait in
+    this client is on a subprocess round trip, and Windows is where these bounds flake.
+  */
   const waitForNotification = <T>(method: string, predicate: (params: T) => boolean, timeoutMs = 15_000) =>
     Effect.gen(function* () {
       while (true) {
-        const received = yield* acp.receive.pipe(Effect.timeout(Duration.millis(timeoutMs)))
+        const received = yield* acp.receive.pipe(Effect.timeout(Duration.millis(slowPlatform(timeoutMs))))
         if (!isJsonRpcNotification<T>(received)) continue
         if (received.method === method && predicate(received.params as T)) return received
       }
diff --git a/packages/redrob/test/cli/acp/lifecycle.test.ts b/packages/redrob/test/cli/acp/lifecycle.test.ts
index eac2693f1e..de606bb0f0 100644
--- a/packages/redrob/test/cli/acp/lifecycle.test.ts
+++ b/packages/redrob/test/cli/acp/lifecycle.test.ts
@@ -6,7 +6,7 @@ import type {
   ResumeSessionResponse,
 } from "@agentclientprotocol/sdk"
 import { Duration, Effect } from "effect"
-import { cliIt } from "../../lib/cli-process"
+import { cliIt, slowPlatform } from "../../lib/cli-process"
 import { expectOk, selectConfigOption } from "./acp-test-client"
 import { createAcpClient, initialize, newSession, verifierConfig } from "./helpers"
 
@@ -18,7 +18,10 @@ describe("redrob acp lifecycle subprocess", () => {
         const acp = yield* redrob.acp()
         acp.close()
 
-        const code = yield* Effect.promise(() => acp.exited).pipe(Effect.timeout(Duration.seconds(5)))
+        /* Scaled: Windows process teardown is slower, and five seconds was tight enough to flake. */
+        const code = yield* Effect.promise(() => acp.exited).pipe(
+          Effect.timeout(Duration.millis(slowPlatform(5_000))),
+        )
         expect(code).toBe(0)
       }),
     60_000,