filename: "card.png",

},

} as never);

expect(runtimeMock.sendRichMessage).toHaveBeenCalledWith(

expect.objectContaining({ replyToMessageId: "message-guid" }),

);

const attachment = readLastAttachment();

expect(attachment?.kind).toBe("buffer");

expect(attachment?.filename).toBe("card.png");

expect(Buffer.from(attachment?.buffer ?? new Uint8Array()).toString()).toBe("PNGDATA");

expect(runtimeMock.sendRichMessage.mock.calls).toStrictEqual([

[

{

chatGuid: "iMessage;+;resolved-ident",

text: "🦞 here it is",

replyToMessageId: "message-guid",

partIndex: undefined,

attachment: {

kind: "buffer",

buffer: Uint8Array.from(Buffer.from("PNGDATA")),

filename: "card.png",

},

options: imsgOptions("iMessage;+;resolved-ident"),

},

],

]);

});

it("falls back to attachment.bin when filename is missing (post-hydration)", async () => {