util: add support for error subclassing and null prototype

[antsmartian]

Handle error subclassing and null prototypes on error.

/cc @BridgeAR

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

[BridgeAR]

This is a good start but I am a bit afraid about manipulating manually created error stacks.

Would you be so kind and add a test for a case similar to this:

class CustomError extends TypeError {
  constructor(message) {
    super(message);
    const stack = this.stack.split('\n');
    stack.shift();
    this.stack = `Awesome stack: message\n${stack.join('\n')}`;
  }
}
const err = new CustomError('foobar');
...

It is very hard to tell what the user intention was or was not. Therefore I suggest to check for if the original start is the name of one of the classes this error inherited from. That way we are safe to replace things we are certain about.

Something similar about the null prototype: I would use a regular expression to add the null prototype information instead of using indexOf(). The user could definitely have used some special information. I would probably go for /^[a-z_-]+: /i but maybe we want to be more conservative and go for /^[a-z_-]*Error: /i.

[antsmartian]

@BridgeAR : Quick question, for the given example:

class CustomError extends TypeError {
  constructor(message) {
    super(message);
    const stack = this.stack.split('\n');
    stack.shift();
    this.stack = `Awesome stack: message\n${stack.join('\n')}`;
  }
}
const err = new CustomError('foobar');

If we do our check with parent error type, then we would keep the stack as it is like:

Awesome stack: message
    at repl:1:13

but I think, we need to print:

CustomError: foobar
   at repl:1:13

What do you think? Or is it ok, for the user to show them what they need?

[antsmartian]

@BridgeAR Ping :)

[antsmartian]

@BridgeAR Friendly remainder 🔉

[antsmartian]

@BridgeAR friendly ping again...

[antsmartian]

@BridgeAR Sorry, but one more very gentle ping.. :)

[BridgeAR]

This case is a duplicate of the test above.

[BridgeAR]

I have to give this one a bit more thought. Sadly, there are lots and lots of edge cases that could happen with errors.

[BridgeAR]

Superseded by #26923. It could still be expanded but I would not want to do that before Node.js v13.