如何更改 firefox javascript 引擎规则？错误处理

Question

function hasLiedAboutBrowser()
{
  // Assume browser is Firefox but user agent fakes Google Chrome browser
  var browser = 'Chrome';
  // We create an error to see how it is handled
  var errFirefox;
  try
  {
    // eslint-disable-next-line no-throw-literal
    throw 'a';
  }
  catch (err)
  {
    try
    {
      console.log('before err.toSource() line'); // This line will work on every browser
      err.toSource();
      console.log('after err.toSource() line'); // This line will work only on Firefox browser
      errFirefox = true; // This line will work only Firefox browser
    }
    catch (errOfErr)
    {
      // if err.toSource() throws an exception browser is not a firefox.
      errFirefox = false;
    }
  }
  if (errFirefox && browser !== 'Firefox' && browser !== 'Other')
  {
    console.log("You lied about your browser.");
  } 
  else
  {
    console.log("All fine");
  }
}
hasLiedAboutBrowser();

此代码告诉我们用户何时对浏览器撒谎。

我需要的是 "change firefox javascript error handling rules" 这样 firefox 就会像其他浏览器一样处理错误

我该怎么做？

1-) 从源代码编译 firefox？（如果是这样，规则可能在哪里？）

2-) 更改 omni.ja 存档文件中的一些 javascript 代码？（不太可能）

知道怎么做吗？

Answer 1

Firefox 在 String 上定义了 toSource，因此只需将其设为未定义即可：

String.prototype.toSource = undefined;

document.getElementsByTagName('button')[0].addEventListener('click', hasLiedAboutBrowser);
document.getElementsByTagName('button')[1].addEventListener('click', function() {
  String.prototype.toSource = undefined;
  console.log('removed toSource from string prototype');
});

function hasLiedAboutBrowser() {
  // Assume browser is Firefox but user agent fakes Google Chrome browser
  var browser = 'Chrome';
  // We create an error to see how it is handled
  var errFirefox;
  try {
    // eslint-disable-next-line no-throw-literal
    throw 'a';
  } catch (err) {
    try {
      console.log('before err.toSource() line'); // This line will work on every browser
      err.toSource();
      console.log('after err.toSource() line'); // This line will work only on Firefox browser
      errFirefox = true; // This line will work only Firefox browser
    } catch (errOfErr) {
      // if err.toSource() throws an exception browser is not a firefox.
      errFirefox = false;
    }
  }
  if (errFirefox && browser !== 'Firefox' && browser !== 'Other') {
    console.log("You lied about your browser.");
  } else {
    console.log("All fine");
  }
}

<button>Check Browser</button>
<button>remove toSource</button>

如何更改 firefox javascript 引擎规则？错误处理

How to change firefox javascript engine rules? Error handling

javascript

browser

error-handling

firefox

gecko