javascript - 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“更改firefox javascript错误处理规则”，以便firefox将像其他浏览器一样处理错误

我怎样才能做到这一点？

1-)从源代码编译Firefox？ (可能的话，规则在哪里？)

2-)更改omni.ja存档文件上的一些javascript代码？ (不见得)

任何想法如何做到这一点？

Answer 1

Firefox在toSource上定义了String，因此只需使其未定义即可:

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>