List Files in Folder

//native

const graph = "https://graph.microsoft.com/v1.0"

function driveUrl(drive_id: string | undefined) {

  return drive_id != null && drive_id !== ""

    ? `${graph}/drives/${encodeURIComponent(drive_id)}`

    : `${graph}/me/drive`

}

// An item is addressed by its id, or by a path from the drive root starting with "/"

function ref(item: string | undefined) {

  if (item == null || item === "" || item === "/") return "root"

  if (!item.startsWith("/")) return `items/${encodeURIComponent(item)}`

  const path = item

    .replace(/\/+$/, "")

    .split("/")

    .map(encodeURIComponent)

    .join("/")

  return `root:${path}:`

}

/**

 * List Files in Folder

 * List the files and folders directly inside a folder (the root when `folder` is empty) in your OneDrive, or in another drive when `drive_id` is set. `folder` is an id, or a path from the drive root starting with "/" (e.g. `/Reports/2026/summary.xlsx`). `filter` and `order_by` take OData (e.g. `name desc`). Pass the returned `@odata.nextLink` as `next_link` for the next page. Requires Files.Read (covered by the default Files.ReadWrite); a drive that is not your own needs Files.Read.All.

 */

export async function main(

  auth: RT.MsOnedrive,

  folder: string | undefined,

  order_by: string | undefined,

  filter: string | undefined,

  select: string | undefined,

  top: number = 100,

  next_link: string | undefined,

  drive_id: string | undefined

) {

  const drive = driveUrl(drive_id)

  if (

    next_link != null &&

    next_link !== "" &&

    !next_link.startsWith("https://graph.microsoft.com/")

  ) {

    throw new Error(

      "next_link must be an @odata.nextLink returned by Microsoft Graph"

    )

  }

  let url: URL

  if (next_link != null && next_link !== "") {

    url = new URL(next_link)

  } else {

    url = new URL(`${drive}/${ref(folder)}/children`)

    url.searchParams.append("$top", String(top))

    if (order_by != null && order_by !== "") {

      url.searchParams.append("$orderby", order_by)

    }

    if (filter != null && filter !== "") {

      url.searchParams.append("$filter", filter)

    }

    if (select != null && select !== "") {

      url.searchParams.append("$select", select)

    }

  }

  const response = await fetch(url, {

    headers: {

      Authorization: `Bearer ${auth.token}`,

      Accept: "application/json",

    },

  })

  if (!response.ok) {

    throw new Error(`${response.status} ${await response.text()}`)

  }

  return await response.json()

}