是否有任何方法关闭我的JavaScript代码中的所有console.log语句,用于测试目的?
当前回答
我这样写道:
//Make a copy of the old console.
var oldConsole = Object.assign({}, console);
//This function redefine the caller with the original one. (well, at least i expect this to work in chrome, not tested in others)
function setEnabled(bool) {
if (bool) {
//Rewrites the disable function with the original one.
console[this.name] = oldConsole[this.name];
//Make sure the setEnable will be callable from original one.
console[this.name].setEnabled = setEnabled;
} else {
//Rewrites the original.
var fn = function () {/*function disabled, to enable call console.fn.setEnabled(true)*/};
//Defines the name, to remember.
Object.defineProperty(fn, "name", {value: this.name});
//replace the original with the empty one.
console[this.name] = fn;
//set the enable function
console[this.name].setEnabled = setEnabled
}
}
不幸的是,它在使用严格模式下不起作用。
使用console。fn。setEnabled = setEnabled然后是console。fn。setEnabled(false) fn可以是几乎任何控制台函数。 你的情况是:
console.log.setEnabled = setEnabled;
console.log.setEnabled(false);
我还写了这个:
var FLAGS = {};
FLAGS.DEBUG = true;
FLAGS.INFO = false;
FLAGS.LOG = false;
//Adding dir, table, or other would put the setEnabled on the respective console functions.
function makeThemSwitchable(opt) {
var keysArr = Object.keys(opt);
//its better use this type of for.
for (var x = 0; x < keysArr.length; x++) {
var key = keysArr[x];
var lowerKey = key.toLowerCase();
//Only if the key exists
if (console[lowerKey]) {
//define the function
console[lowerKey].setEnabled = setEnabled;
//Make it enabled/disabled by key.
console[lowerKey].setEnabled(opt[key]);
}
}
}
//Put the set enabled function on the original console using the defined flags and set them.
makeThemSwitchable(FLAGS);
所以你只需要在FLAGS中加入默认值(在执行上面的代码之前),比如FLAGS. log = false,日志功能将在默认情况下被禁用,仍然可以调用console.log.setEnabled(true)来启用它
其他回答
如果你使用IE7,控制台将不会被定义。所以一个更IE友好的版本是:
if (typeof console == "undefined" || typeof console.log == "undefined")
{
var console = { log: function() {} };
}
我认为2020年最简单、最容易理解的方法是创建一个像log()这样的全局函数,你可以选择以下方法之一:
const debugging = true;
function log(toLog) {
if (debugging) {
console.log(toLog);
}
}
function log(toLog) {
if (true) { // You could manually change it (Annoying, though)
console.log(toLog);
}
}
你可以说这些功能的缺点是:
您仍然在运行时调用函数 您必须记住在第二个选项中更改调试变量或if语句 您需要确保在加载所有其他文件之前加载了该函数
And my retorts to these statements is that this is the only method that won't completely remove the console or console.log function which I think is bad programming because other developers who are working on the website would have to realize that you ignorantly removed them. Also, you can't edit JavaScript source code in JavaScript, so if you really want something to just wipe all of those from the code you could use a minifier that minifies your code and removes all console.logs. Now, the choice is yours, what will you do?
当使用React时,你可以利用钩子来管理它,这样它就被限制在你的组件范围内
import { useEffect, useRef } from "react";
type LoggingReplacements = {
debug?: typeof console["debug"];
error?: typeof console["error"];
info?: typeof console["info"];
log?: typeof console["log"];
warn?: typeof console["warn"];
};
/**
* This replaces console.XXX loggers with custom implementations. It will restore console log on unmount of the component.
* @param replacements a map of replacement loggers. They're all optional and only the functions defined will be replaced.
*/
export function useReplaceLogging({
debug,
error,
info,
log,
warn,
}: LoggingReplacements): void {
const originalConsoleDebug = useRef(console.debug);
const originalConsoleError = useRef(console.error);
const originalConsoleInfo = useRef(console.info);
const originalConsoleLog = useRef(console.log);
const originalConsoleWarn = useRef(console.warn);
if (debug) {
console.debug = debug;
}
if (error) {
console.error = error;
}
if (info) {
console.info = info;
}
if (log) {
console.log = log;
}
if (warn) {
console.warn = warn;
}
useEffect(() => {
return function restoreConsoleLog() {
console.debug = originalConsoleDebug.current;
console.error = originalConsoleError.current;
console.info = originalConsoleInfo.current;
console.log = originalConsoleLog.current;
console.warn = originalConsoleWarn.current;
};
}, []);
}
在https://github.com/trajano/react-hooks/tree/master/src/useReplaceLogging上编写测试代码
你可以使用javascript AOP(例如jquery-aop)来拦截所有对console.debug/log的调用,如果某个全局变量被设置为false,就不进行实际的调用。
您甚至可以(不时地)执行ajax调用,这样就可以更改服务器上启用/禁用日志的行为,当在登台环境或类似环境中遇到问题时启用调试,这可能非常有趣。
下面是更详细的:
var DEBUG = false;
if(!DEBUG){
if(!window.console) window.console = {};
var methods = ["log", "debug", "warn", "info"];
for(var i=0;i<methods.length;i++){
console[methods[i]] = function(){};
}
}
这将把控制台中存在的通用方法归零,并且可以毫无错误地调用它们,而且几乎没有性能开销。在像IE6这样没有控制台的浏览器的情况下,将创建虚拟方法以防止错误。当然,Firebug中还有更多的函数,比如跟踪、配置文件、时间等。如果在代码中使用它们,则可以将它们添加到列表中。
你也可以检查调试器是否有这些特殊的方法(ie, ie),并将不支持的方法归零:
if(window.console && !console.dir){
var methods = ["dir", "dirxml", "trace", "profile"]; //etc etc
for(var i=0;i<methods.length;i++){
console[methods[i]] = function(){};
}
}