Function makeClientMetadata

src/cmap/handshake/client_metadata.ts:108–184

(
  driverInfoList: DriverInfo[],
  { appName = '', runtime: { os } }: MakeClientMetadataOptions
)

 * 4. Truncate `platform`. -- special we do not truncate this field
 */
export async function makeClientMetadata(
  driverInfoList: DriverInfo[],
  { appName = '', runtime: { os } }: MakeClientMetadataOptions
): Promise<ClientMetadata> {
  const metadataDocument = new LimitedSizeDocument(512);

  // Add app name first, it must be sent
  if (appName.length > 0) {
    const name =
      ByteUtils.utf8ByteLength(appName) <= 128
        ? appName
        : ByteUtils.toUTF8(ByteUtils.fromUTF8(appName), 0, 128, false);
    metadataDocument.ifItFitsItSits('application', { name });
  }

  const driverInfo = {
    name: 'nodejs',
    version: NODE_DRIVER_VERSION
  };

  // This is where we handle additional driver info added after client construction.
  for (const { name: n = '', version: v = '' } of driverInfoList) {
    if (n.length > 0) {
      driverInfo.name = `${driverInfo.name}|${n}`;
    }
    if (v.length > 0) {
      driverInfo.version = `${driverInfo.version}|${v}`;
    }
  }

  if (!metadataDocument.ifItFitsItSits('driver', driverInfo)) {
    throw new MongoInvalidArgumentError(
      'Unable to include driverInfo name and version, metadata cannot exceed 512 bytes'
    );
  }

  let runtimeInfo = getRuntimeInfo();
  // This is where we handle additional driver info added after client construction.
  for (const { platform = '' } of driverInfoList) {
    if (platform.length > 0) {
      runtimeInfo = `${runtimeInfo}|${platform}`;
    }
  }

  if (!metadataDocument.ifItFitsItSits('platform', runtimeInfo)) {
    throw new MongoInvalidArgumentError(
      'Unable to include driverInfo platform, metadata cannot exceed 512 bytes'
    );
  }

  // Note: order matters, os.type is last so it will be removed last if we're at maxSize
  const osInfo = new Map()
    .set('name', os.platform())
    .set('architecture', os.arch())
    .set('version', os.release())
    .set('type', os.type());

  if (!metadataDocument.ifItFitsItSits('os', osInfo)) {