Function readAttachFileFromPath

src/node/utils/attachments/readAttachmentFromPath.ts:264–339

(
  args: ReadAttachmentFromPathArgs
)

}

export async function readAttachFileFromPath(
  args: ReadAttachmentFromPathArgs
): Promise<AttachFileFromPathResult> {
  assert(
    typeof args.path === "string" && args.path.trim().length > 0,
    "attach_file requires a path"
  );

  const { resolvedPath } = resolvePathWithinCwd(args.path, args.cwd, args.runtime);
  const fileStat = await statRegularFile(args, resolvedPath);
  const filename = getFallbackFilename(resolvedPath, args.filename);
  const mediaType = getSupportedAttachmentMediaType({
    mediaType: args.mediaType,
    // Infer the attachment type from the source path, not the display filename override.
    // Callers may intentionally rename the attachment to a presentation-only label.
    filename: resolvedPath,
  });

  if (mediaType == null) {
    const displayMediaTypeCandidate = getDisplayFileMediaTypeCandidate(args, resolvedPath);
    if (displayMediaTypeCandidate == null) {
      throw createUnsupportedAttachmentError(args, resolvedPath);
    }
    if (fileStat.size > MAX_ATTACH_FILE_SIZE_BYTES) {
      throw new Error(
        `${getErrorMessage(createUnsupportedAttachmentError(args, resolvedPath))}. Could not show file to user: ${buildTooLargeMessage(fileStat.size)}`
      );
    }

    const bytes = await readRegularFileBytes(args, resolvedPath, fileStat.size);
    if (displayMediaTypeCandidate.requireBinaryContent && isLikelyTextFile(bytes)) {
      throw createUnsupportedAttachmentError(args, resolvedPath);
    }

    return {
      type: "display",
      file: createLoadedFile({
        data: bytes,
        mediaType: displayMediaTypeCandidate.mediaType,
        filename,
        resolvedPath,
      }),
    };
  }

  const bytes = await readRegularFileBytes(args, resolvedPath, fileStat.size);

  if (mediaType === SVG_MEDIA_TYPE) {
    const svgText = bytes.toString("utf8");
    if (svgText.length > MAX_SVG_TEXT_CHARS) {
      throw new Error(
        `SVG attachments must be ${MAX_SVG_TEXT_CHARS.toLocaleString()} characters or less (this one is ${svgText.length.toLocaleString()}).`
      );
    }
  }

  let attachmentBytes = bytes;
  let attachmentMediaType = mediaType;