alibaba/open-code-review · error

%w%s

Error message

%w%s

What it means

flagErrorWithSuggestion takes a cobra unknown-flag error, extracts the unknown flag name, and when suggestFlag finds a close match, appends the suggestion to the original error with fmt.Errorf("%w%s", err, suggestion). The result is an error like `unknown flag: --outpu` plus `\n\nDid you mean this?\n\t--output`, and it still wraps the original err (errors.Is/As keep working).

Source

Thrown at cmd/opencodereview/flag_suggest.go:29

	"github.com/spf13/pflag"
)

// flagErrorWithSuggestion is a SetFlagErrorFunc handler that appends a
// "Did you mean?" suggestion when the user misspells a flag.
func flagErrorWithSuggestion(cmd *cobra.Command, err error) error {
	msg := err.Error()

	var unknown string
	if strings.HasPrefix(msg, "unknown flag: ") {
		unknown = strings.TrimPrefix(msg, "unknown flag: ")
		unknown = strings.TrimLeft(unknown, "-")
	}
	if unknown == "" {
		return err
	}

	if suggestion := suggestFlag(cmd, unknown); suggestion != "" {
		return fmt.Errorf("%w%s", err, suggestion)
	}
	return err
}

func suggestFlag(cmd *cobra.Command, unknown string) string {
	unknown = strings.TrimLeft(unknown, "-")
	if unknown == "" {
		return ""
	}

	var best string
	bestDist := 3 // max edit distance to consider
	cmd.Flags().VisitAll(func(f *pflag.Flag) {
		d := levenshtein(unknown, f.Name)
		if d < bestDist {
			bestDist = d
			best = f.Name
		}

View on GitHub (pinned to 5cf97d0d15)

Solutions

1. Read the 'Did you mean this?' line appended to the error and rerun with the suggested flag
2. Run `ocr <cmd> --help` to list valid flags
3. Use shell completion or tab-completion for flag names

Example fix

// before
ocr review --audince agent
// after
ocr review --audience agent

func flagExists(cmd *cobra.Command, name string) bool {
    return cmd.Flags().Lookup(strings.TrimLeft(name, "-")) != nil
}

if err := cmd.Execute(); err != nil {
    if strings.Contains(err.Error(), "unknown flag") {
        fmt.Fprintln(os.Stderr, err) // includes appended 'Did you mean this?' hint
    }
    os.Exit(1)
}

When it happens

Trigger: Typing a misspelled flag on any ocr command, e.g. `ocr review --audince agent` — cobra returns the unknown-flag error and this helper augments it with the nearest known flag.

Common situations: Simple typos; abbreviating flags when the exact short form does not exist; muscle memory from other CLIs (e.g. --message vs --msg).

Related errors

• unknown provider field %q: supported fields are api_key, api
• only one review mode allowed (--from/--to or --commit)
• --to is required when --from is specified
• --from is required when --to is specified
• invalid --audience value %q: must be 'human' or 'agent'

AI-assisted analysis of alibaba/open-code-review@5cf97d0d15 (2026-09-02). Data as JSON: /api/errors/fa775905c56465a6. Report an issue: GitHub.