@davidosborn/crypto-tax-calculator/lib/csv-normalize-stream.js

A tool to calculate the capital gains of cryptocurrency assets for Canadian taxes

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = _default;

var _stream = _interopRequireDefault(require("stream"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**
 * A stream that normalizes the delimiters of a CSV file.
 */
class CsvNormalizeStream extends _stream.default.Transform {
  /**
   * Initializes a new instance.
   */
  constructor() {
    super();
    this._delimiter = null;
  }
  /**
   * Normalizes the delimiters of a CSV file.
   * @param {buffer|string} chunk    The CSV file.
   * @param {string}        encoding The encoding type.
   * @param {function}      callback A callback for when the transformation is complete.
   */


  async _transform(chunk, encoding, callback) {
    let line = chunk.toString().trim(); // Determine the delimiter from the header.

    if (this._delimiter == null) this._delimiter = line.split('\t').length > line.split(',').length ? '\t' : ',';

    if (this._delimiter !== ',') {
      // It should be safe to drop the existing commas.
      line = line.replace(/,/g, ''); // Replace the delimiter with a comma.

      if (this._delimiter === '\t') line = line.replace(/\t/g, ',');else {
        let i = -1;

        while (true) {
          line = line.replace(this._delimiter, ',');
          let j = line.lastIndexOf(',');
          if (j === i) break;
          i = j;
        }
      }
    }

    this.push(line + '\n');
    callback();
  }

}

function _default(...args) {
  return new CsvNormalizeStream(...args);
}