gohugoio/hugo · error

transform.Highlight: expects at most 3 arguments

Error message

transform.Highlight: expects at most 3 arguments

What it means

`transform.Highlight` takes the code to highlight plus up to two more arguments: a language and an options string/map. Its variadic tail is limited to two extra values; when more than three total arguments are supplied, the switch falls into the default case and returns this error.

Source

Thrown at tpl/transform/transform.go:136

			opts = args[0]
		} else {
			var arg string
			if arg, err = cast.ToStringE(args[0]); err != nil {
				return "", err
			}
			if strings.Contains(arg, "=") || strings.Contains(arg, ",") {
				opts = arg
			} else {
				lang = arg
			}
		}
	case 2:
		if lang, err = cast.ToStringE(args[0]); err != nil {
			return "", err
		}
		opts = args[1]
	default:
		return "", errors.New("transform.Highlight: expects at most 3 arguments")
	}

	hl := ns.deps.ContentSpec.Converters.GetHighlighter()
	highlighted, err := hl.Highlight(code, lang, opts)
	if err != nil {
		return "", err
	}
	return template.HTML(highlighted), nil
}

// HighlightCodeBlock highlights a code block on the form received in the codeblock render hooks.
func (ns *Namespace) HighlightCodeBlock(ctx hooks.CodeblockContext, opts ...any) (highlight.HighlightResult, error) {
	var optsv any
	if len(opts) > 0 {
		optsv = opts[0]
	}

	hl := ns.deps.ContentSpec.Converters.GetHighlighter()

View on GitHub ↗ (pinned to 8a468df065)

Solutions

1. Combine options into a single argument: `{{ highlight $code "go" "linenos=true,style=monokai" }}`.
2. Or pass a dict: `{{ highlight $code "go" (dict "lineNos" true "style" "monokai") }}`.
3. Drop any extra positional arguments beyond code, lang, and one options value.

Example fix

<!-- before -->
{{ highlight $code "go" "linenos=true" "style=monokai" }}
<!-- after -->
{{ highlight $code "go" "linenos=true,style=monokai" }}

{{/* highlight takes code, lang, and at most one options argument */}}
{{ $opts := "linenos=table,hl_lines=1-3" }}
{{ highlight $code "go" $opts }}

When it happens

Trigger: Calling `{{ highlight $code "go" "linenos=true" "style=monokai" }}` — i.e. passing language plus more than one options argument, or any call with 4+ arguments.

Common situations: Splitting options into separate arguments instead of one comma-separated string or dict; porting shortcode-style `{{< highlight go "linenos=true" >}}` syntax into a template function call with extra positional args.

Related errors

• failed to detect format from content
• failed to detect target data serialization format
• need at least 2 arguments to append
• must provide a Resource and optionally an options map
• operator argument must be string type

AI-assisted analysis of gohugoio/hugo@8a468df065 (2026-07-31). Data as JSON: /data/errors/23b879f64ecbd828.json. Report an issue: GitHub ↗.