gqlerr

This package was developed by Silicon Ally while working on a project for Adventure Scientists. Many thanks to Adventure Scientists for supporting our open source mission!

gqlerr

gqlerr is a package for handling errors in a Go/gqlgen-based GraphQL server. It integrates logging via *zap.Logger so that all errors are logged. Codes are modeled after the gRPC error codes.

Usage

To use this package, set the gqlerr.ErrorPresenter as your server.SetErrorPresenter with your already-configured *zap.Logger instance. See the gqlgen error docs for more info.

From there, start replacing errors in handlers with calls to gqlerr. For example, if you have code like:

func (r *Resolver) SomeResolver(ctx context.Context, req model.Request) (*model.Response, error) {
  if err := validate(req); err != nil {
    return nil, fmt.Errorf("failed to validate request: %w", err)
  }
  return &model.Response{}, nil
}

You'd update it to the following:

func (r *Resolver) SomeResolver(ctx context.Context, req model.Request) (*model.Response, error) {
  if err := validate(req); err != nil {
    return nil, gqlerr.
      InvalidArgument("request failed validation", zap.Error(err)).
      WithMessage("invalid request")
  }
  return &model.Response{}, nil
}

This error will get transformed into a standard GraphQL {"errors": [ ... ]}, with the message given by WithMessage. By default, a generic message similar to net/http's StatusText(...) function will be returned. A log message will also be written to the logger, at an appropriate log level for the error code if one is not explicitly supplied with At{Debug,Info,Warn,Error}Level().