brand short code light dark test for #12365

this was not a pure refactor; it did introduce another parameter to the brand color shortcode
at shortcode time there is no user or auther preference, this just defaults to light

Author: gordonwoodhull

news/changelog-1.7.md

@@ -121,6 +121,7 @@ All changes included in 1.7:
 - ([#11896](https://github.com/quarto-dev/quarto-cli/pull/11896)): fix `\f` (`{{< pagebreak >}}`) form feed character not valid in PowerPoint (`pptx`).
 - ([#11664](https://github.com/quarto-dev/quarto-cli/issues/11664)): `lipsum` shortcode is no longer randomly generated by default, use `{{< lipsum random=true >}}` to restore randomness.
 - ([#11379](https://github.com/quarto-dev/quarto-cli/issues/11379)): Add `version` shortcode to display the current Quarto version.
+- ([#12365](https://github.com/quarto-dev/quarto-cli/pull/12365)): `brand color` shortcode takes an optional `brandMode` second parameter, default `light`.
 - ([#12326](https://github.com/quarto-dev/quarto-cli/issues/12326)): Add `quarto.shortcode.*` API entry points for shortcode developers.
 
 ## Quarto Lua API

tests/docs/shortcodes/brand-light-dark.qmd

@@ -0,0 +1,38 @@
+---
+title: Test brand light/dark shortcodes
+format: html
+brand:
+  light:
+    color:
+      palette:
+        blue: "#82aeef"
+      background: '#fff8ee'
+      foreground: '#116423'
+  dark:
+    color:
+      palette:
+        blue: "#415777"
+      background: '#071217'
+      foreground: '#ffeecc'
+_quarto:
+  tests:
+    html:
+      ensureHtmlElements:
+        -
+          - 'div#default-brand[style="background-color: #82aeef"]'
+          - 'div#light-brand[style="background-color: #82aeef"]'
+          - 'div#dark-brand[style="background-color: #415777"]'
+        - []
+---
+
+::: {#default-brand style='background-color: {{< brand color blue >}}'}
+Default brand blue background.
+:::
+
+::: {#light-brand style='background-color: {{< brand color blue light >}}'}
+Light brand blue background.
+:::
+
+::: {#dark-brand style='background-color: {{< brand color blue dark >}}'}
+Dark brand blue background.
+:::