).toBe("Thread starter body");

});

it("truncates long thread starter bodies on code-point boundaries", () => {

const summary = summarizeMatrixThreadStarterEvent({

event_id: "$root",

sender: "@alice:example.org",

type: "m.room.message",

origin_server_ts: Date.now(),

content: {

msgtype: "m.text",

// 496 "a" + astral emoji (surrogate pair at units 496-497) + tail.

// A raw slice(0, 497) would cut the pair and leave a lone high surrogate.

body: `${"a".repeat(496)}\u{1F600}bcd`,

},

} as MatrixRawEvent);

expect(summary).toBe(`${"a".repeat(496)}...`);

expect(summary && /[\uD800-\uDFFF]/.test(summary)).toBe(false);

});

it("marks media-only thread starter events instead of returning bare filenames", () => {

expect(

summarizeMatrixThreadStarterEvent({

// Matrix plugin module implements thread context behavior.

import { sliceUtf16Safe } from "openclaw/plugin-sdk/text-utility-runtime";

import type { MatrixClient } from "../sdk.js";

import { summarizeMatrixMessageContextEvent, trimMatrixMaybeString } from "./context-summary.js";

import type { MatrixRawEvent } from "./types.js";

if (value.length <= MAX_THREAD_STARTER_BODY_LENGTH) {

return value;

}

return `${value.slice(0, MAX_THREAD_STARTER_BODY_LENGTH - 3)}...`;

return `${sliceUtf16Safe(value, 0, MAX_THREAD_STARTER_BODY_LENGTH - 3)}...`;

}

export function summarizeMatrixThreadStarterEvent(event: MatrixRawEvent): string | undefined {