Tweak scss-docs shortcode

site/layouts/shortcodes/scss-docs.html

@@ -1,33 +1,38 @@
 {{- /*
   Usage: `scss-docs name="name" file="file/_location.scss"`
 
-    Prints everything between `// scss-docs-start "name"` and `// scss-docs-end "name"`
-    comments in the docs.
+  Prints everything between `// scss-docs-start "name"` and `// scss-docs-end "name"`
+  comments in the docs.
 
-    Optional parameters:
-    strip-default: Remove the ` !default` flag from variable assignments - default: `true`
+  Optional parameters:
+    * strip-default: Remove the ` !default` flag from variable assignments - default: `true`
 */ -}}
 
 {{- $name := .Get "name" -}}
 {{- $file := .Get "file" -}}
 {{- $strip_default := .Get "strip-default" | default "true" -}}
 
-{{- $start := printf "// scss-docs-start %s\n" $name -}}
-{{- $end := printf "\n// scss-docs-end %s" $name -}}
-{{- $regex := printf "%s(.|\n)*%s" $start $end -}}
+{{- /* If any parameters are missing, print an error and exit */ -}}
+{{- if or (not $name) (not $file) -}}
+  {{- errorf "Missing required parameters! Got: name=%q file=%q! (called in %q)" $name $file $.Page.Path -}}
+{{- else -}}
+  {{- $start := printf "// scss-docs-start %s\n" $name -}}
+  {{- $end := printf "\n// scss-docs-end %s" $name -}}
+  {{- $regex := printf "%s(.|\n)*%s" $start $end -}}
 
-{{- $css := readFile $file -}}
-{{- $match := findRE $regex $css 1 -}}
+  {{- $css := readFile $file -}}
+  {{- $match := findRE $regex $css 1 -}}
 
-{{- if (eq (len $match) 0) -}}
-  {{- errorf "Got no matches for %q in %q! (called in %q)" $name $file $.Page.Path -}}
-{{- end -}}
+  {{- if (eq (len $match) 0) -}}
+    {{- errorf "Got no matches for name=%q in file=%q! (called in %q)" $name $file $.Page.Path -}}
+  {{- end -}}
 
-{{- $remove_start := replace (index $match 0) $start "" -}}
-{{- $result := replace $remove_start $end "" -}}
+  {{- $remove_start := replace (index $match 0) $start "" -}}
+  {{- $result := replace $remove_start $end "" -}}
 
-{{- if (ne $strip_default "false") -}}
-  {{- $result = replace $result " !default" "" -}}
-{{- end -}}
+  {{- if (ne $strip_default "false") -}}
+    {{- $result = replace $result " !default" "" -}}
+  {{- end -}}
 
-{{- highlight $result "scss" "" -}}
+  {{- highlight $result "scss" "" -}}
+{{- end -}}