app/themes/hugo-theme-stack/layouts/partials/helper/icon.html

{{- $iconFile := resources.GetMatch (printf "icons/%s.svg" .) -}}
{{- if $iconFile -}}
    {{- $iconFile.Content | safeHTML -}}
{{- else -}}
    {{- errorf "Error: icon '%s.svg' is not found under 'assets/icons' folder" . -}}
{{- end -}}