migration-sql-parse.js

'use strict';

// Constants
const kDefaultDelimiter = '\n-- MIGRATION DOWN SQL\n';

/**
 * @param {String} migrationSql
 * @param {String} [optDelimiter='\n-- MIGRATION DOWN SQL\n']
 * @returns {Object.<{up, down}}
 */
module.exports = function(migrationSql, optDelimiter = kDefaultDelimiter) {
  if (!migrationSql)
    throw new Error('Missing / empty migration SQL argument');

  if (typeof migrationSql !== 'string')
    throw new Error(`migration SQL must be string; got ${typeof migrationSql} instead`);

  let delimiter = optDelimiter || exports.kDefaultDelimiter,
    delimiterPosition = migrationSql.indexOf(delimiter),
    upSql = null,
    downSql = null;

  if (delimiterPosition >= 0) {
    upSql = migrationSql.substr(0, delimiterPosition);
    downSql = migrationSql.substr(delimiterPosition);
  }
  else {
    upSql = migrationSql;
  }

  return {
    up: upSql,
    down: downSql,
  };
};
module.exports.kDefaultDelimiter = kDefaultDelimiter;