fix(discord): cover thread binding persona names

ly85206559 · ly85206559 · commit 89d8eb2b487b · 2026-07-07T21:03:14.000+08:00
diff --git a/extensions/discord/src/monitor/thread-bindings.persona.test.ts b/extensions/discord/src/monitor/thread-bindings.persona.test.ts
@@ -6,6 +6,24 @@ import {
 } from "./thread-bindings.persona.js";
 import type { ThreadBindingRecord } from "./thread-bindings.types.js";
 
+function hasLoneSurrogate(value: string): boolean {
+  for (let index = 0; index < value.length; index += 1) {
+    const code = value.charCodeAt(index);
+    if (code >= 0xd800 && code <= 0xdbff) {
+      const next = value.charCodeAt(index + 1);
+      if (!(next >= 0xdc00 && next <= 0xdfff)) {
+        return true;
+      }
+      index += 1;
+      continue;
+    }
+    if (code >= 0xdc00 && code <= 0xdfff) {
+      return true;
+    }
+  }
+  return false;
+}
+
 describe("thread binding persona", () => {
   it("prefers explicit label and prefixes with gear", () => {
     expect(resolveThreadBindingPersona({ label: "codex thread", agentId: "codex" })).toBe(
@@ -32,4 +50,23 @@ describe("thread binding persona", () => {
     } satisfies ThreadBindingRecord;
     expect(resolveThreadBindingPersonaFromRecord(record)).toBe("⚙️ codex-thread");
   });
+  it("keeps thread binding webhook personas on a UTF-16 boundary", () => {
+    const record = {
+      accountId: "default",
+      channelId: "parent-1",
+      threadId: "thread-1",
+      targetKind: "acp",
+      targetSessionKey: "agent:codex:acp:session-1",
+      agentId: "codex",
+      boundBy: "system",
+      boundAt: Date.now(),
+      lastActivityAt: Date.now(),
+      label: `${"a".repeat(77)}\u{1f63e}tail`,
+    } satisfies ThreadBindingRecord;
+
+    const persona = resolveThreadBindingPersonaFromRecord(record);
+
+    expect(persona.length).toBeLessThanOrEqual(80);
+    expect(hasLoneSurrogate(persona)).toBe(false);
+  });
 });
diff --git a/extensions/discord/src/monitor/thread-bindings.persona.ts b/extensions/discord/src/monitor/thread-bindings.persona.ts
@@ -1,5 +1,6 @@
 // Discord plugin module implements thread bindings.persona behavior.
 import { SYSTEM_MARK } from "openclaw/plugin-sdk/text-chunking";
+import { truncateUtf16Safe } from "openclaw/plugin-sdk/text-utility-runtime";
 import type { ThreadBindingRecord } from "./thread-bindings.types.js";
 
 const THREAD_BINDING_PERSONA_MAX_CHARS = 80;
@@ -15,7 +16,7 @@ function normalizePersonaLabel(value: string | undefined): string | undefined {
 export function resolveThreadBindingPersona(params: { label?: string; agentId?: string }): string {
   const base =
     normalizePersonaLabel(params.label) || normalizePersonaLabel(params.agentId) || "agent";
-  return `${SYSTEM_MARK} ${base}`.slice(0, THREAD_BINDING_PERSONA_MAX_CHARS);
+  return truncateUtf16Safe(`${SYSTEM_MARK} ${base}`, THREAD_BINDING_PERSONA_MAX_CHARS);
 }
 
 export function resolveThreadBindingPersonaFromRecord(record: ThreadBindingRecord): string {
