Function getMessageFileRefs

packages/bot-teams/src/graph-files.ts:103–133

Read a channel message and return its file-reference attachments.

(
  ref: ChannelMessageRef,
  token: string,
)

/** Read a channel message and return its file-reference attachments. */
async function getMessageFileRefs(
  ref: ChannelMessageRef,
  token: string,
): Promise<GraphFileRef[]> {
  const channel = encodeURIComponent(ref.channelId);
  const url =
    ref.rootId && ref.rootId !== ref.messageId
      ? `${GRAPH}/teams/${ref.teamId}/channels/${channel}/messages/${ref.rootId}/replies/${ref.messageId}`
      : `${GRAPH}/teams/${ref.teamId}/channels/${channel}/messages/${ref.messageId}`;
  const res = await fetch(url, {
    headers: { Authorization: `Bearer ${token}` },
  });
  if (!res.ok) {
    throw new Error(
      `read channel message failed (HTTP ${res.status}): ${(await res.text()).slice(0, 200)}`,
    );
  }
  const msg = (await res.json()) as {
    attachments?: Array<{
      contentType?: string;
      contentUrl?: string;
      name?: string;
    }>;
  };
  return (msg.attachments ?? [])
    .filter(
      (a): a is { contentType: string; contentUrl: string; name?: string } =>
        a.contentType === "reference" && typeof a.contentUrl === "string",
    )
    .map((a) => ({ name: a.name ?? "file", contentUrl: a.contentUrl }));
}

/** Download a SharePoint file by its sharing URL via the Graph `/shares` API. */
async function downloadSharedFile(