Oops, Errors

Error handling for adding attributes, error codes, and source location to errors when logging them.

Inspired by https://github.com/samber/oops with a minimal API.

Works with log/slog through a LogValue that decorates the logged error attribute with the attributes and source location to any oops.Error.

Example

func (s *Service)process(ctx context.Context, id string) error {
    now := time.Now()
    if id == "" {
        return oops.New("process failed: bad input").Code(400)
    }

    results, err := s.Run(ctx, id)
    if err != nil {
        if errors.Is(err, context.DeadlineExceeded) {
            return oops.Errorf("process failed: deadline exceeded %w", err).With("duration", time.Since(now))
        }
        return oops.Wrap(err).With("id", id, "method", "Run")
    }

    return results, nil
}

func main() {
    ctx := context.Background()
    logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))
    s := &Service{}

    _, err := s.process(ctx, "oops")
    if err != nil {
         if oops.Code(err) == 400 {
             logger.Warn("process input rejected", "error", err)
         } else {
             logger.Error("process failed", "error", err)
         }
    }
}

{
   "time":"2025-02-01T21:59:54.959869-07:00",
   "level":"ERROR",
   "msg":"process failed",
   "error":{
      "err":"process not found",
      "id":"oops",
      "method":"Run",
      "source":[
         {
            "file":"#####/github.com/jesse0michael/oops/README.md",
            "function":"github.com/jesse0michael/oops.process",
            "line":30
         }
      ]
   }
}

This example highlights some of the different ways to create and decorate errors by dropping in the oops package. Create a new error with oops.New or wrap an existing error with oops.Wrap or use oops.Errorf to format an error message.

Add attributes to the error with the With method. The With method can take any number of key-value pairs or slog.Attr's.

Set error codes with the Code method to indicate specific error types or status codes. You can retrieve the error code using the oops.Code() function, which returns the explicitly set code or looks for a "code" attribute set as an integer.

Wrapping or formatting an oops.Error with %w will append the source location with the new error and preserve attributes of any prior error.

Includes a slog Handler that will preserve the specified error field used with the oops.Error as the string representation of the inner error, and add the error decoration to the slog key oops.

logger := slog.New(oops.NewOopsHandler(slog.NewJSONHandler(os.Stdout, nil)))

{
   "time":"2025-02-01T21:59:54.959869-07:00",
   "level":"ERROR",
   "msg":"process failed",
   "error": "process not found",
   "oops":{
      "id":"oops",
      "method":"Run",
      "source":[
         {
            "file":"#####/github.com/jesse0michael/oops/README.md",
            "function":"github.com/jesse0michael/oops.process",
            "line":30
         }
      ]
   }
}

Note

runtime source location can be disabled with oops.EnableSource(false).

The slog handler attribute field can be overridden with oops.SetAttrField("field").