fix(telegram): use Array.from instead of spread for code point length validation (#111443)

extensions/telegram/src/send-forum-topics.ts

@@ -49,7 +49,7 @@ export async function editForumTopicTelegram(
   if (nameProvided && !trimmedName) {
     throw new Error("Telegram forum topic name is required");
   }
-  if (trimmedName && trimmedName.length > 128) {
+  if (trimmedName && Array.from(trimmedName).length > 128) {
     throw new Error("Telegram forum topic name must be 128 characters or fewer");
   }
   const iconProvided = opts.iconCustomEmojiId !== undefined;
@@ -177,7 +177,7 @@ export async function createForumTopicTelegram(
     throw new Error("Forum topic name is required");
   }
   const trimmedName = name.trim();
-  if (trimmedName.length > 128) {
+  if (Array.from(trimmedName).length > 128) {
     throw new Error("Forum topic name must be 128 characters or fewer");
   }
 

extensions/telegram/src/send.test.ts

@@ -826,6 +826,31 @@ describe("sendMessageTelegram", () => {
     });
   });
 
+  it.each([
+    ["65 emoji", "😀".repeat(65)],
+    ["128 emoji", "😀".repeat(128)],
+    ["128 mixed emoji and ASCII characters", "😀".repeat(64) + "a".repeat(64)],
+    ["128 CJK characters", "界".repeat(128)],
+  ])("accepts %s forum topic names by Unicode code points", async (_label, name) => {
+    loadConfig.mockReturnValue({
+      channels: {
+        telegram: {
+          botToken: "tok",
+        },
+      },
+    });
+    botApi.editForumTopic.mockResolvedValue(true);
+
+    await editForumTopicTelegram("-1001234567890", 271, {
+      cfg: TELEGRAM_TEST_CFG,
+      token: "tok",
+      accountId: "default",
+      name,
+    });
+
+    expect(botApi.editForumTopic).toHaveBeenCalledWith("-1001234567890", 271, { name });
+  });
+
   it("strips topic suffixes before editing a Telegram forum topic", async () => {
     loadConfig.mockReturnValue({
       channels: {
@@ -5106,6 +5131,24 @@ describe("createForumTopicTelegram", () => {
     });
   }
 
+  it.each([
+    ["65 emoji", "🎃".repeat(65)],
+    ["128 emoji", "🎃".repeat(128)],
+    ["128 mixed emoji and ASCII characters", "🎃".repeat(64) + "a".repeat(64)],
+    ["128 CJK characters", "界".repeat(128)],
+  ])("accepts %s forum topic names by Unicode code points", async (_label, name) => {
+    const createForumTopic = vi.fn().mockResolvedValue({ message_thread_id: 400, name });
+    const api = { createForumTopic } as unknown as Bot["api"];
+
+    await createForumTopicTelegram("-1001234567890", name, {
+      cfg: TELEGRAM_TEST_CFG,
+      token: "tok",
+      api,
+    });
+
+    expect(createForumTopic).toHaveBeenCalledWith("-1001234567890", name, undefined);
+  });
+
   it("rejects an invalid topic name before creating a Telegram client", async () => {
     botCtorSpy.mockClear();
 
@@ -5117,5 +5160,34 @@ describe("createForumTopicTelegram", () => {
     ).rejects.toThrow("Forum topic name is required");
     expect(botCtorSpy).not.toHaveBeenCalled();
   });
+
+  it.each([
+    ["129 ASCII characters", "a".repeat(129)],
+    ["129 emoji", "🎃".repeat(129)],
+    ["19 multi-code-point emoji graphemes", "👨‍👩‍👧‍👦".repeat(19)],
+  ])("rejects %s exceeding 128 Unicode code points on create and edit", async (_label, name) => {
+    const createForumTopic = vi.fn();
+    const editForumTopic = vi.fn();
+    const api = { createForumTopic, editForumTopic } as unknown as Bot["api"];
+
+    await expect(
+      createForumTopicTelegram("-1001234567890", name, {
+        cfg: TELEGRAM_TEST_CFG,
+        token: "tok",
+        api,
+      }),
+    ).rejects.toThrow("128 characters or fewer");
+    await expect(
+      editForumTopicTelegram("-1001234567890", 271, {
+        cfg: TELEGRAM_TEST_CFG,
+        token: "tok",
+        api,
+        name,
+      }),
+    ).rejects.toThrow("128 characters or fewer");
+
+    expect(createForumTopic).not.toHaveBeenCalled();
+    expect(editForumTopic).not.toHaveBeenCalled();
+  });
 });
 /* oxlint-disable max-lines -- TODO: split this grandfathered oversized file. */