to-csv.js

var CsvBuilder = require("csv-builder");

function new_normalizeArray_(data_row) {
  var csved_row = data_row.map((column_data) => {
    let text_data = column_data != null ? column_data.toString() : '';
    if (this.format.delimiter === "\t") {
      text_data = text_data.replace(/\t/g, "");
    } else if (this.format.delimiter === ",") {
      if (
        text_data.includes(",") ||
        text_data.includes("\n") ||
        text_data.includes('"')
      ) {
        if (text_data.includes('"')) {
          text_data = text_data.replace(/"/g, '""');
        }
        text_data = `"${text_data}"`;
      }
    }
    return text_data;
  });
  return csved_row;
}

// If options.show_headers == false OR undefined then do not return header names in output
function forgetHeader_() {
  return "";
}

/**
 * Create csv streams from a mongoose schema
 * @param {mongoose.Schema} schema
 * @param {Object} options CsvBuilder options
 * @param {String|Array} options.headers Space separated headers, or array of headers
 * @param {String} [options.delimiter = ','] Value delimiter for csv data
 * @param {String} [options.terminator = '\n'] Line terminator for csv data
 * @param {Object} options.constraints {"header": "prop"}
 * @param {Object} options.virtuals Virtual properties.
 */

module.exports = function mongooseToCsv(schema, options) {
  // need options.headers
  if (!options.headers)
    throw new Error("MongooseToCsv requires the `headers` option");
  var builder = new CsvBuilder(options);
  builder._normalizeArray = new_normalizeArray_;

  if (typeof options.show_headers === "undefined" || !options.show_headers) {
    builder.getHeaders = forgetHeader_;
  }

  if (options.virtuals) {
    for (var v in options.virtuals) {
      builder.virtual(v, options.virtuals[v]);
    }
  }

  /**
   * Static Method `csvReadStream`
   * @param {Array<Documents>} docs Array of mongoose documents
   * @return {Stream} Csv read stream.
   */

  schema.static("csvReadStream", function (docs) {
    if (!docs) {
      throw new Error("[Model].csvReadStream requires an array of documents.");
    }
    var data = docs.map(function (obj) {
      return obj._doc;
    });
    return builder.createReadStream(data);
  });

  /**
   * Create a Csv stream from a query Object.
   * @param {Object} query Mongoose query
   * @return {Stream} Csv transform stream
   */

  schema.static("findAndStreamCsv", function (query) {
    query = query || {};

    return this.find(query).cursor().pipe(builder.createTransformStream());
  });

  /**
   * Create a transform stream
   * @return {Stream} transform stream
   */

  schema.static("csvTransformStream", function () {
    return builder.createTransformStream();
  });
};