fix(sdk): fallback for AbortSignal.any in chat transport on Safari < 17.4 (#5098)

packages/trigger-sdk/src/v3/ai-shared.test.ts

@@ -0,0 +1,93 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { anySignal } from "./ai-shared.js";
+
+describe("anySignal", () => {
+  it("returns a non-aborted signal when signals list is empty", () => {
+    const signal = anySignal([]);
+    expect(signal.aborted).toBe(false);
+  });
+
+  it("filters out null and undefined values", () => {
+    const controller = new AbortController();
+    const signal = anySignal([null, undefined, controller.signal, null]);
+    expect(signal).toBe(controller.signal);
+  });
+
+  it("returns the single signal if only one valid signal is provided", () => {
+    const controller = new AbortController();
+    const signal = anySignal([controller.signal]);
+    expect(signal).toBe(controller.signal);
+  });
+
+  describe("when AbortSignal.any is available (native)", () => {
+    it("aborts when any of the input signals aborts", () => {
+      const c1 = new AbortController();
+      const c2 = new AbortController();
+      const combined = anySignal([c1.signal, c2.signal]);
+
+      expect(combined.aborted).toBe(false);
+      c2.abort("cancelled by c2");
+      expect(combined.aborted).toBe(true);
+      expect(combined.reason).toBe("cancelled by c2");
+    });
+  });
+
+  describe("fallback when AbortSignal.any is undefined (Safari < 17.4, Node < 20.3)", () => {
+    const originalAny = AbortSignal.any;
+
+    beforeEach(() => {
+      // @ts-expect-error - simulating environment without AbortSignal.any
+      delete AbortSignal.any;
+    });
+
+    afterEach(() => {
+      AbortSignal.any = originalAny;
+    });
+
+    it("returns an immediately aborted signal if an input signal is already aborted", () => {
+      const c1 = new AbortController();
+      const c2 = new AbortController();
+      c1.abort("already aborted reason");
+
+      const combined = anySignal([c1.signal, c2.signal]);
+      expect(combined.aborted).toBe(true);
+      expect(combined.reason).toBe("already aborted reason");
+    });
+
+    it("aborts when the first signal is aborted", () => {
+      const c1 = new AbortController();
+      const c2 = new AbortController();
+      const combined = anySignal([c1.signal, c2.signal]);
+
+      expect(combined.aborted).toBe(false);
+      c1.abort("first reason");
+      expect(combined.aborted).toBe(true);
+      expect(combined.reason).toBe("first reason");
+    });
+
+    it("aborts when the second signal is aborted", () => {
+      const c1 = new AbortController();
+      const c2 = new AbortController();
+      const combined = anySignal([c1.signal, c2.signal]);
+
+      expect(combined.aborted).toBe(false);
+      c2.abort("second reason");
+      expect(combined.aborted).toBe(true);
+      expect(combined.reason).toBe("second reason");
+    });
+
+    it("cleans up event listeners on remaining signals when one signal aborts", () => {
+      const c1 = new AbortController();
+      const c2 = new AbortController();
+
+      const c2RemoveSpy = vi.spyOn(c2.signal, "removeEventListener");
+      const combined = anySignal([c1.signal, c2.signal]);
+
+      expect(combined.aborted).toBe(false);
+      c1.abort("first aborted");
+
+      expect(combined.aborted).toBe(true);
+      expect(c2RemoveSpy).toHaveBeenCalledWith("abort", expect.any(Function));
+    });
+  });
+});

packages/trigger-sdk/src/v3/ai-shared.ts

@@ -278,3 +278,50 @@ export function waitBeforeEofResubscribe(attempt: number, signal: AbortSignal):
     if (signal.aborted) done();
   });
 }
+
+/**
+ * Combines multiple AbortSignals into a single signal.
+ *
+ * Uses native `AbortSignal.any` when available, and falls back to an AbortController
+ * with listeners on environments where `AbortSignal.any` is not supported (such as
+ * Safari < 17.4 or Node < 20.3).
+ */
+export function anySignal(signals: (AbortSignal | undefined | null)[]): AbortSignal {
+  const validSignals = signals.filter((s): s is AbortSignal => s != null);
+  const first = validSignals[0];
+  if (!first) {
+    return new AbortController().signal;
+  }
+  if (validSignals.length === 1) {
+    return first;
+  }
+  if (typeof AbortSignal !== "undefined" && typeof AbortSignal.any === "function") {
+    return AbortSignal.any(validSignals);
+  }
+
+  const controller = new AbortController();
+  const alreadyAborted = validSignals.find((s) => s.aborted);
+  if (alreadyAborted) {
+    controller.abort(alreadyAborted.reason);
+    return controller.signal;
+  }
+
+  const onAbort = (e: Event) => {
+    const s = e.target as AbortSignal;
+    controller.abort(s?.reason);
+    cleanup();
+  };
+
+  const cleanup = () => {
+    for (const s of validSignals) {
+      s.removeEventListener("abort", onAbort);
+    }
+  };
+
+  for (const signal of validSignals) {
+    signal.addEventListener("abort", onAbort, { once: true });
+  }
+
+  return controller.signal;
+}
+

packages/trigger-sdk/src/v3/ai.ts

@@ -136,6 +136,7 @@ import {
   type InferChatClientData,
   type InferChatUIMessage,
   type InferChatUIMessageFromTools,
+  anySignal,
   BACKGROUND_INJECTION_TYPE,
   PENDING_MESSAGE_INJECTED_TYPE,
   upsertIncomingMessage,
@@ -11072,7 +11073,7 @@ function chatAgent<
                 // Three signals for the user's run function
                 const stopSignal = stopController.signal;
                 const cancelSignal = runSignal;
-                const combinedSignal = AbortSignal.any([runSignal, stopController.signal]);
+                const combinedSignal = anySignal([runSignal, stopController.signal]);
 
                 const pmConfig = locals.get(chatPendingMessagesKey);
                 /**
@@ -15859,7 +15860,7 @@ function createChatSession<TClientData = unknown>(
             return { done: true, value: undefined };
           }
 
-          const combinedSignal = AbortSignal.any([runSignal, stop.signal]);
+          const combinedSignal = anySignal([runSignal, stop.signal]);
 
           const turnObj: ChatTurn<TClientData> = {
             number: turn,

packages/trigger-sdk/src/v3/chat-client.ts

@@ -31,6 +31,7 @@ import {
 } from "@trigger.dev/core/v3";
 import type { ChatInputChunk, ChatTaskWirePayload } from "./ai-shared.js";
 import {
+  anySignal,
   chatRunTags,
   MAX_EOF_RESUBSCRIBES,
   slimSubmitMessageForWire,
@@ -815,7 +816,7 @@ export class AgentChat<TAgent = unknown> {
 
     const internalAbort = new AbortController();
     const combinedSignal = abortSignal
-      ? AbortSignal.any([abortSignal, internalAbort.signal])
+      ? anySignal([abortSignal, internalAbort.signal])
       : internalAbort.signal;
 
     // Detached once the stream ends (see the `finally` below): a caller reusing

packages/trigger-sdk/src/v3/chat-server.ts

@@ -79,7 +79,7 @@ import type {
   UIMessageChunk,
 } from "ai";
 import type { ChatInputChunk, ChatTaskWirePayload } from "./ai-shared.js";
-import { chatRunTags } from "./ai-shared.js";
+import { anySignal, chatRunTags } from "./ai-shared.js";
 import { triggerConcurrencyBody } from "./concurrency-shared.js";
 import { withResolvedExternalDeploymentId } from "./externalDeploymentId.js";
 import type { SessionTriggerConfigInput } from "./sessions.js";
@@ -970,7 +970,7 @@ async function openHandoverSession(opts: {
             "out",
             {
               ...(customerLastEventId != null ? { lastEventId: customerLastEventId } : {}),
-              signal: AbortSignal.any([abortController.signal, subscriptionAbort.signal]),
+              signal: anySignal([abortController.signal, subscriptionAbort.signal]),
               onPart: (part) => {
                 if (part.id) latestEventId = part.id;
               },

packages/trigger-sdk/src/v3/chat.test.ts

@@ -2456,6 +2456,25 @@ describe("TriggerChatTransport", () => {
         vi.useRealTimers();
       }
     });
+
+    it("safely reconnects and aborts when AbortSignal.any is not supported (Safari < 17.4)", async () => {
+      const originalAny = AbortSignal.any;
+      try {
+        // @ts-expect-error - simulating older browser/runtime without AbortSignal.any
+        delete AbortSignal.any;
+
+        const { transport } = quietWatchTransport();
+        const abort = new AbortController();
+        const stream = await transport.reconnectToStream({
+          chatId: "chat-own",
+          abortSignal: abort.signal,
+        });
+        expect(stream).toBeDefined();
+        abort.abort();
+      } finally {
+        AbortSignal.any = originalAny;
+      }
+    });
   });
 
   describe("superseded stream teardown", () => {

packages/trigger-sdk/src/v3/chat.ts

@@ -46,6 +46,7 @@ function byteLength(body: string): number {
 }
 import { ChatTabCoordinator } from "./chat-tab-coordinator.js";
 import {
+  anySignal,
   MAX_EOF_RESUBSCRIBES,
   slimSubmitMessageForWire,
   waitBeforeEofResubscribe,
@@ -1355,7 +1356,7 @@ export class TriggerChatTransport implements ChatTransport<UIMessage> {
     this.activeStreams.set(options.chatId, abortController);
 
     const abortSignal = options.abortSignal
-      ? AbortSignal.any([options.abortSignal, abortController.signal])
+      ? anySignal([options.abortSignal, abortController.signal])
       : abortController.signal;
 
     return this.subscribeToSessionStream(state, abortSignal, options.chatId, {
@@ -2064,7 +2065,7 @@ export class TriggerChatTransport implements ChatTransport<UIMessage> {
     let didSettle = false;
     this.activeStreams.set(chatId, internalAbort);
     const combinedSignal = abortSignal
-      ? AbortSignal.any([abortSignal, internalAbort.signal])
+      ? anySignal([abortSignal, internalAbort.signal])
       : internalAbort.signal;
 
     if (abortSignal) {