将所有控制台 javascript 输出转储为字符串

Question

我有一个问题，我需要获取所有 console.log 输出是否可以将所有 console.log 输出转储到一个变量？我使用 node.js。一点上下文：我有一个 mocha 记者的输出，我希望将所有输​​出格式化并通过电子邮件发送

Answer 1

基于@godot 的回答：

var logs = '' // logs needs to be defined for the += operator
const tmp = console.log
console.log = function(...args) {
  // string substitution, console.log style
  const formatArg = util.format(...args)
  logs += formatArg + '\n'
  tmp(...args)
}

// To test it :

console.log('test1')
// use console.log with the "printf" style
console.log('test%d', 2)
// same
console.log('%s%d', 'test', 3)
// now show all the logs that were collected in the global var logs variable
console.log('logs: ', logs) // if you don't like globals, u can also use put it in an attribute of the console object...

Answer 2

您可以使用一种技巧，将console.log 替换为decorator pattern 之后的另一个函数：

var logs = ''; // logs needs to be defined for the += operator
const tmp = console.log;
console.log = function(...args){ 
    logs += arg + ' '
    tmp(...args)
}

显然，使用全局变量不是很好，但您可以从那里改进...