Terminal-Hugo-Theme/layouts/shortcodes/code.html

{{ $id := delimit (shuffle (seq 1 9)) "" }}
{{ $open := .Get "open" }}
{{ $lang := .Get "language" }}
{{ $opts := .Get "opts" }}

{{- if $lang -}}
  <details class="collapsable-code" {{ if eq $open "true" -}} open {{- end }}>
    <summary title="Click to interact">
      {{- if .Get "title" }}<span class="collapsable-code__title">{{ .Get "title" | markdownify }}</span>{{ end -}}
    </summary>
    {{ $trInner := trim .Inner "\n" }}
    {{- transform.Highlight $trInner $lang $opts -}}
  </details>
{{ else }}
  {{ errorf "If you want to use the \"collapsable code\" shortcode, you need to pass a mandatory \"language\" param. The issue occured in %q (%q)" .Page.File .Page.Permalink }}
{{- end -}}