fix(telegram): preserve legacy prefixed messaging targets

src/channels/plugins/normalize/telegram.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+import { looksLikeTelegramTargetId, normalizeTelegramMessagingTarget } from "./telegram.js";
+
+describe("normalizeTelegramMessagingTarget", () => {
+  it("normalizes t.me links to prefixed usernames", () => {
+    expect(normalizeTelegramMessagingTarget("https://t.me/MyChannel")).toBe("telegram:@mychannel");
+  });
+
+  it("keeps legacy prefixed topic targets valid", () => {
+    expect(normalizeTelegramMessagingTarget("telegram:group:-1001234567890:topic:456")).toBe(
+      "telegram:group:-1001234567890:topic:456",
+    );
+    expect(normalizeTelegramMessagingTarget("tg:group:-1001234567890:topic:456")).toBe(
+      "telegram:group:-1001234567890:topic:456",
+    );
+  });
+});
+
+describe("looksLikeTelegramTargetId", () => {
+  it("recognizes legacy prefixed topic targets", () => {
+    expect(looksLikeTelegramTargetId("telegram:group:-1001234567890:topic:456")).toBe(true);
+    expect(looksLikeTelegramTargetId("tg:group:-1001234567890:topic:456")).toBe(true);
+  });
+
+  it("still recognizes normalized lookup targets", () => {
+    expect(looksLikeTelegramTargetId("https://t.me/MyChannel")).toBe(true);
+    expect(looksLikeTelegramTargetId("@mychannel")).toBe(true);
+  });
+});

src/channels/plugins/normalize/telegram.ts

@@ -1,13 +1,32 @@
 import { normalizeTelegramLookupTarget } from "../../../telegram/targets.js";
 
 export function normalizeTelegramMessagingTarget(raw: string): string | undefined {
-  const normalized = normalizeTelegramLookupTarget(raw);
+  const trimmed = raw.trim();
+  if (!trimmed) {
+    return undefined;
+  }
+
+  const normalized = normalizeTelegramLookupTarget(trimmed);
   if (!normalized) {
+    // Keep legacy prefixed targets (including :topic: suffixes) valid.
+    if (/^(telegram|tg):/i.test(trimmed)) {
+      const stripped = trimmed.replace(/^(telegram|tg):/i, "").trim();
+      if (stripped) {
+        return `telegram:${stripped}`.toLowerCase();
+      }
+    }
     return undefined;
   }
   return `telegram:${normalized}`.toLowerCase();
 }
 
 export function looksLikeTelegramTargetId(raw: string): boolean {
-  return Boolean(normalizeTelegramLookupTarget(raw));
+  const trimmed = raw.trim();
+  if (!trimmed) {
+    return false;
+  }
+  if (normalizeTelegramLookupTarget(trimmed)) {
+    return true;
+  }
+  return /^(telegram|tg):/i.test(trimmed);
 }