errorownership

What it detects

Handle an error at one layer. The analyzer also catches inline error declarations whose condition accidentally checks a different error before returning the newly declared one.

Checks

Check	What it detects
log-and-return*	Reports functions that both log and return the same error.
text-classification	Reports production code that classifies errors by matching their text.
mismatched-inline-error	Reports inline error declarations whose condition checks a different error.

* Opt-in; requires explicit selection.

Why this is flagged

Handling the same error at several layers often creates duplicate logs or reports, while checking the wrong variable can silently ignore a real failure. Each layer should either add context and return the error or handle it fully.

How to fix it

Choose one responsibility at each layer: return the error with useful context, or report and fully handle it there. When declaring an error inside an if, make sure the condition checks that newly declared error.

Examples

Flagged code

func load() error {
  if err := readConfig(); err != nil {
    // gohawk: error is logged and returned by same function
    log.Print(err)
    return err
  }
  return nil
}

Accepted code

func loadWithContext() error {
  if err := readConfig(); err != nil {
    return fmt.Errorf("read config: %w", err)
  }
  return nil
}