Error wrapping and returned error types...

[sean-]

First things first: thank you for the library. It's very interesting and promising. I've used it a few times in the last week with good success but noticed something in practice that I wanted to bring up.

import (
  "github.com/rs/zerolog/log"
  "github.com/pkg/errors"
)

func myFunc() error {
  if err := someMethod(); err != nil {
    log.Error().Err(err).Str("some detail", "my details").Msg("something bad")
    return errors.Wrapf(err, "something bad: some details")
  }

  return nil
}

Would you be interested in an Error() or Errorf() event processor that would return an error object? I'm already in the error path at this point in time and am less concerned about performance.

I'm hoping to arrive at something like the following in order to reduce redundant code:

import (
  "github.com/rs/zerolog/log"
  "github.com/pkg/errors"
)

func myFunc() error {
  if err := someMethod(); err != nil {
    return log.Error().Err(err).Str("some detail", "my details").Stacktrace().Error("something bad")
  }

  return nil
}

The thinking being that tStacktrace() would capture the current stack trace and include it in the error object returned to the caller, and the Error() event handler would return a wrapped error similar to github.com/pkg/errors, github.com/hashicorp/errwrap, github.com/contiv/errored.

Thoughts? Thanks in advance!

[soulne4ny]

I would suggest support for error wrappers like errors.Wrap() of http://github.com/pkg/errors or https://github.com/go-errors/errors, or any of their combination. It would be nice to have an easy way to provide zerolog.Event.Err() with custom formatter for a particular error type.

Probably it could be done with a test for kind of zerolog.ErrorMarshaler interface. Would it be cheap enough to afford it for every log.Error().Err(err) call?

[rs]

If anything, it would have to be in a separate package as I don't want to force external deps on people using zerolog.

[rs]

See discussion in #11

[rs]

Fixed by #35