JavaScript Evaluation Error

try {
    eval(somejavascript);
} catch(e) {
    console.log(e);
}

When I encounter runtime errors like:

TypeError: Cannot call method 'leftPad' of undefined

I wonder if there is any way to debug this error. Specifically, I'm looking for a solution that can provide the character position/line number where the error occurs in the evaluated expression, as well as a stack trace.

The stack trace provided by Chrome stops at the eval function.

Unfortunately, I am unable to debug my sample JavaScript code by putting it into a separate file due to the fact that the runtime error doesn't occur when including the code in an HTML document.

javascript

Answer №1

It seems like your issue is more focused on diagnosing the problem rather than finding a solution.

If that's the case, you can handle it by enclosing the code in a try-catch block (for debugging purposes only):

let javascriptCode = 'function baz() { let foo; foo.leftPad(); } baz();';

eval('try { ' + javascriptCode + ' } catch(error) { console.log(error.stack); }');

You can experiment with it here.

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