add-multiple-column-in-sequelize-migration.js

module.exports = {
  up: function (queryInterface, Sequelize) {
    return [
      queryInterface.addColumn('User', 'name', {
        type: Sequelize.STRING
      }),
      queryInterface.addColumn('User', 'nickname', {
        type: Sequelize.STRING,
      })
    ];
  },

  down: function (queryInterface, Sequelize) {
    return [
      queryInterface.removeColumn('Challenges', 'name'),
      queryInterface.removeColumn('Challenges', 'nickname')
    ];
  }
};

migrate function should return promise so add Promise.all

module.exports = {
  up: function (queryInterface, Sequelize) {
    return Promise.all([
      queryInterface.addColumn('User', 'name', {
        type: Sequelize.STRING
      }),
      queryInterface.addColumn('User', 'nickname', {
        type: Sequelize.STRING,
      })
    ]);
  },

  down: function (queryInterface, Sequelize) {
    return Promise.all([
      queryInterface.removeColumn('User', 'name'),
      queryInterface.removeColumn('User', 'nickname')
    ]);
  }
};