Function csvLoader

packages/csv/src/csv-loader.ts:43–128

({
  fileName,
  idField,
  transformHeader = camelize,
  parserOptions,
}: CSVLoaderOptions)

 * Loads entries from a CSV file. The file must contain an array of objects that contain unique `id` fields, or an object with string keys.
 */
export function csvLoader({
  fileName,
  idField,
  transformHeader = camelize,
  parserOptions,
}: CSVLoaderOptions): Loader {
  async function syncData(
    filePath: string,
    { logger, parseData, store, config }: LoaderContext,
  ) {
    const relativePath = relative(fileURLToPath(config.root), filePath);

    const csvStream = Papa.parse(Papa.NODE_STREAM_INPUT, {
      dynamicTyping: true,
      ...parserOptions,
      header: true,
      transformHeader: transformHeader === false ? undefined : transformHeader,
    });

    createReadStream(filePath).pipe(csvStream);

    await new Promise<void>((resolve, reject) => {
      let count = 0;
      let row = 0;
      store.clear();
      csvStream.on("end", () => {
        logger.info(`Loaded ${count} entries from ${fileName}`);
        resolve();
      });
      csvStream.on("error", (error) => {
        logger.error("Error reading data");
        reject(error);
      });
      csvStream.on("data", async (data) => {
        if (!idField) {
          idField = Object.keys(data)[0];
          logger.info(`No ID field specified, using first column: ${idField}`);
          if (!idField) {
            csvStream.end();
            reject("No ID field found in CSV file");
            return;
          }
        }
        row++;
        if (!(idField in data) || !(data[idField] && data[idField] !== 0)) {
          logger.warn(`No ID (${idField}) found in row ${row}. Skipping.`);
          return;
        }
        count++;
        const id = String(data[idField]);
        const parsedData = await parseData({
          id,
          data,
          filePath: relativePath,
        });
        store.set({ id, data: parsedData, filePath: relativePath });
      });
    }).catch((error) => {