diff --git a/src/infra/jsonl-socket.test.ts b/src/infra/jsonl-socket.test.ts
index 3524a3f9d4d..17922dc167f 100644
--- a/src/infra/jsonl-socket.test.ts
+++ b/src/infra/jsonl-socket.test.ts
@@ -20,6 +20,11 @@ async function listenOnSocket(server: net.Server, socketPath: string): Promise<b
   }
 }
 
+function acceptDoneValue(msg: unknown): number | null | undefined {
+  const value = msg as { type?: string; value?: number };
+  return value.type === "done" ? (value.value ?? null) : undefined;
+}
+
 describe.runIf(process.platform !== "win32")("requestJsonlSocket", () => {
   it("ignores malformed and non-accepted lines until one is accepted", async () => {
     await withTempDir({ prefix: "openclaw-jsonl-socket-" }, async (dir) => {
@@ -42,10 +47,7 @@ describe.runIf(process.platform !== "win32")("requestJsonlSocket", () => {
             socketPath,
             requestLine: '{"hello":"world"}',
             timeoutMs: 500,
-            accept: (msg) => {
-              const value = msg as { type?: string; value?: number };
-              return value.type === "done" ? (value.value ?? null) : undefined;
-            },
+            accept: acceptDoneValue,
           }),
         ).resolves.toBe(42);
       } finally {
@@ -79,10 +81,7 @@ describe.runIf(process.platform !== "win32")("requestJsonlSocket", () => {
             socketPath,
             requestLine: '{"hello":"world"}',
             timeoutMs: 500,
-            accept: (msg) => {
-              const value = msg as { type?: string; value?: number };
-              return value.type === "done" ? (value.value ?? null) : undefined;
-            },
+            accept: acceptDoneValue,
           }),
         ).resolves.toBe(7);
         expect(receivedBuffer).toBe('{"hello":"world"}\n');