Strategy for name property given uglification?

[ckknight]

Given that name is determined via this.constructor.name, if one were to minify their code and mangle the names, this could lead to new MyCustomError().name === 'e'.

[bjyoungblood]

The short answer

I hadn't really considered this. I originally built this library with the only intention of using it in Bluebird's .catch predicate filters (e.g. .catch(NotFoundError, (err) => { ... })).

This isn't ideal, but if you're using uglifyjs2, there are a few options available that might solve this for you quickly:

• keep_fnames / --keep-fnames disables mangling of function names (easier, but obviously results in less minification)
• reserved allows you to provide a list of identifiers that should not be mangled (harder to maintain)

---

The long answer

I've given a some thought to this library lately. I consider it to be a hack, and I'm not really a fan of hacks. Given the number of ways that it can break or fail to work as intended (uglifying, use with typescript, issues with different module bundlers, cross-environment issues, changes to babel, etc.), I would almost recommend not using it.

A much simpler pattern that involves zero hacks could look something like this:

const notFound = 'NotFoundError';

function notFoundError(err) {
  err.name = notFound;
  return err;
}

function isNotFoundError(err) {
  return err.name === notFound;
}

try {
  throw notFoundError(new Error('message'));
} catch(err) {
  if (isNotFoundError(err)) {
    // handle
  } else {
    // handle other
  }
}

This should still capture the correct stack trace and message, while preserving the error name. You could also create other decorator functions to add additional info/properties to the error.

[bjyoungblood]

Added a link to this issue in the readme. Closing for now.