From 9882f1c919db73229965e0b897861d1e400ea960 Mon Sep 17 00:00:00 2001
From: Justin Spahr-Summers <justin@anthropic.com>
Date: Thu, 14 Nov 2024 14:25:16 +0000
Subject: [PATCH] Add `abortAfterTimeout()` utility to make it easy to add
 timeouts

---
 src/shared/protocol.ts |  2 ++
 src/utils.test.ts      | 15 +++++++++++++++
 src/utils.ts           | 11 +++++++++++
 3 files changed, 28 insertions(+)
 create mode 100644 src/utils.test.ts
 create mode 100644 src/utils.ts

diff --git a/src/shared/protocol.ts b/src/shared/protocol.ts
index ab8421bf..8103695d 100644
--- a/src/shared/protocol.ts
+++ b/src/shared/protocol.ts
@@ -48,6 +48,8 @@ export type RequestOptions = {
 
   /**
    * Can be used to cancel an in-flight request. This will cause an AbortError to be raised from request().
+   *
+   * Use abortAfterTimeout() to easily implement timeouts using this signal.
    */
   signal?: AbortSignal;
 };
diff --git a/src/utils.test.ts b/src/utils.test.ts
new file mode 100644
index 00000000..e4aa4e5f
--- /dev/null
+++ b/src/utils.test.ts
@@ -0,0 +1,15 @@
+import { abortAfterTimeout } from "./utils.js";
+
+describe("abortAfterTimeout", () => {
+  it("should abort after timeout", () => {
+    const signal = abortAfterTimeout(0);
+    expect(signal.aborted).toBe(false);
+
+    return new Promise((resolve) => {
+      setTimeout(() => {
+        expect(signal.aborted).toBe(true);
+        resolve(true);
+      }, 0);
+    });
+  });
+});
diff --git a/src/utils.ts b/src/utils.ts
new file mode 100644
index 00000000..11672ecd
--- /dev/null
+++ b/src/utils.ts
@@ -0,0 +1,11 @@
+/**
+ * Returns an AbortSignal that will enter aborted state after `timeoutMs` milliseconds.
+ */
+export function abortAfterTimeout(timeoutMs: number): AbortSignal {
+  const controller = new AbortController();
+  setTimeout(() => {
+    controller.abort();
+  }, timeoutMs);
+
+  return controller.signal;
+}