test(slack): prove inbound preview UTF-16 boundary

steipete · steipete · commit 5817f8f30031 · 2026-07-09T08:53:41.000+01:00
diff --git a/extensions/slack/src/monitor/message-handler/prepare.test.ts b/extensions/slack/src/monitor/message-handler/prepare.test.ts
@@ -188,6 +188,14 @@ describe("slack prepareSlackMessage inbound contract", () => {
     expect(prepared.ctxPayload.BodyForAgent).toContain(body);
   });
 
+  it("keeps inbound previews UTF-16 safe at the truncation boundary", async () => {
+    const prefix = "a".repeat(159);
+    const prepared = await prepareWithDefaultCtx(createSlackMessage({ text: `${prefix}😀tail` }));
+
+    assertPrepared(prepared);
+    expect(prepared.preview).toBe(prefix);
+  });
+
   it("logs inbound metadata without logging message content", async () => {
     const body = "confidential acquisition target: northstar; do not include this text in logs";
     shouldLogVerboseMock.mockReturnValue(true);
diff --git a/extensions/slack/src/monitor/message-handler/prepare.ts b/extensions/slack/src/monitor/message-handler/prepare.ts
@@ -1,3 +1,4 @@
+// Slack plugin module implements prepare behavior.
 import {
   resolveAckReaction,
   shouldAckReaction as shouldAckReactionGate,
@@ -34,7 +35,6 @@ import {
   normalizeOptionalString,
 } from "openclaw/plugin-sdk/string-coerce-runtime";
 import { enqueueSystemEvent } from "openclaw/plugin-sdk/system-event-runtime";
-// Slack plugin module implements prepare behavior.
 import { truncateUtf16Safe } from "openclaw/plugin-sdk/text-utility-runtime";
 import { resolveSlackReplyToMode } from "../../account-reply-mode.js";
 import type { ResolvedSlackAccount } from "../../accounts.js";
