Promiseで逐次実行する時のテスト

var Promise = require('es6-promise').Promise; var tasks = { first: function(value) { return new Promise(function(resolve, reject) { if (value < 2) { resolve(value + 1); } else { reject(new Error('failed at first')); } }); }, second: function(value) { return new Promise(function(resolve, reject) { i…