text: 'use strict'
  
  module.exports = {
    up: (queryInterface, Sequelize) => {
      /*
        Add altering commands here.
        Return a promise to correctly handle asynchronicity.
  
        Example:
        return queryInterface.createTable('users', { id: Sequelize.INTEGER });
      */
      let userIdChange = queryInterface.addColumn('Files', 'userId', {
        type: Sequelize.BIGINT,
        allowNull: true,
        index: true
      })
  
      let trackIdChange = queryInterface.changeColumn('Files', 'trackId', {
        allowNull: true,
        type: Sequelize.BIGINT,
        index: true
      })
  
      return Promise.all([userIdChange, trackIdChange])
    },
  
    down: (queryInterface, Sequelize) => {
      /*
        Add reverting commands here.
        Return a promise to correctly handle asynchronicity.
  
        Example:
        return queryInterface.dropTable('users');
      */
      let undoUserIdChange = queryInterface.removeColumn('Files', 'userId', {
        type: Sequelize.BIGINT,
        allowNull: true,
        index: true
      })
  
      let undoTrackIdChange = queryInterface.changeColumn('Files', 'trackId', {
        allowNull: false,
        type: Sequelize.BIGINT,
        index: true
      })
  
      return Promise.all([undoUserIdChange, undoTrackIdChange])
    }
  }
  