From 411494faa86b6280f3da2c5bc7e7a3089b875205 Mon Sep 17 00:00:00 2001
From: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>
Date: Fri, 27 Mar 2026 23:33:48 -0500
Subject: [PATCH] fix(regression): guard malformed telegram reaction payloads

---
 extensions/telegram/src/status-reaction-variants.ts | 3 +++
 extensions/telegram/src/status.test.ts              | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/extensions/telegram/src/status-reaction-variants.ts b/extensions/telegram/src/status-reaction-variants.ts
index 89b10691d81..5362451ab5d 100644
--- a/extensions/telegram/src/status-reaction-variants.ts
+++ b/extensions/telegram/src/status-reaction-variants.ts
@@ -170,6 +170,9 @@ export function extractTelegramAllowedEmojiReactions(
     // Explicitly omitted/null => all emoji reactions are allowed in this chat.
     return null;
   }
+  if (!Array.isArray(availableReactions)) {
+    return new Set<string>();
+  }
 
   const allowed = new Set<string>();
   for (const reaction of availableReactions) {
diff --git a/extensions/telegram/src/status.test.ts b/extensions/telegram/src/status.test.ts
index 38261182597..d5b32750392 100644
--- a/extensions/telegram/src/status.test.ts
+++ b/extensions/telegram/src/status.test.ts
@@ -157,6 +157,14 @@ describe("extractTelegramAllowedEmojiReactions", () => {
     });
     expect(result ? Array.from(result).toSorted() : null).toEqual(["👍", "🔥"]);
   });
+
+  it("treats malformed available_reactions payloads as an empty allowlist instead of throwing", () => {
+    expect(
+      extractTelegramAllowedEmojiReactions({
+        available_reactions: { type: "emoji", emoji: "👍" },
+      } as never),
+    ).toEqual(new Set<string>());
+  });
 });
 
 describe("resolveTelegramAllowedEmojiReactions", () => {