fix(imessage): normalize messaging targets (#1708)

Co-authored-by: Aaron Ng <1653630+aaronn@users.noreply.github.com>

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

@@ -0,0 +1,15 @@
+import { describe, expect, it } from "vitest";
+
+import { normalizeIMessageMessagingTarget } from "./imessage.js";
+
+describe("imessage target normalization", () => {
+  it("preserves service prefixes for handles", () => {
+    expect(normalizeIMessageMessagingTarget("sms:+1 (555) 222-3333")).toBe("sms:+15552223333");
+  });
+
+  it("drops service prefixes for chat targets", () => {
+    expect(normalizeIMessageMessagingTarget("sms:chat_id:123")).toBe("chat_id:123");
+    expect(normalizeIMessageMessagingTarget("imessage:CHAT_GUID:abc")).toBe("chat_guid:abc");
+    expect(normalizeIMessageMessagingTarget("auto:ChatIdentifier:foo")).toBe("chat_identifier:foo");
+  });
+});

src/channels/plugins/normalize/imessage.ts

@@ -0,0 +1,35 @@
+import { normalizeIMessageHandle } from "../../../imessage/targets.js";
+
+// Service prefixes that indicate explicit delivery method; must be preserved during normalization
+const SERVICE_PREFIXES = ["imessage:", "sms:", "auto:"] as const;
+const CHAT_TARGET_PREFIX_RE =
+  /^(chat_id:|chatid:|chat:|chat_guid:|chatguid:|guid:|chat_identifier:|chatidentifier:|chatident:)/i;
+
+export function normalizeIMessageMessagingTarget(raw: string): string | undefined {
+  const trimmed = raw.trim();
+  if (!trimmed) return undefined;
+
+  // Preserve service prefix if present (e.g., "sms:+1555" → "sms:+15551234567")
+  const lower = trimmed.toLowerCase();
+  for (const prefix of SERVICE_PREFIXES) {
+    if (lower.startsWith(prefix)) {
+      const remainder = trimmed.slice(prefix.length).trim();
+      const normalizedHandle = normalizeIMessageHandle(remainder);
+      if (!normalizedHandle) return undefined;
+      if (CHAT_TARGET_PREFIX_RE.test(normalizedHandle)) return normalizedHandle;
+      return `${prefix}${normalizedHandle}`;
+    }
+  }
+
+  const normalized = normalizeIMessageHandle(trimmed);
+  return normalized || undefined;
+}
+
+export function looksLikeIMessageTargetId(raw: string): boolean {
+  const trimmed = raw.trim();
+  if (!trimmed) return false;
+  if (/^(imessage:|sms:|auto:)/i.test(trimmed)) return true;
+  if (CHAT_TARGET_PREFIX_RE.test(trimmed)) return true;
+  if (trimmed.includes("@")) return true;
+  return /^\+?\d{3,}$/.test(trimmed);
+}