feat: Add support for theme fixture option

Author: GZolla

src/browser/reset.js

@@ -18,6 +18,7 @@ let
 	currentMathjaxRenderLatex = DEFAULT_MATHJAX_RENDER_LATEX,
 	currentMedia = DEFAULT_MEDIA,
 	currentRtl = false,
+	currentTheme = 'light',
 	currentViewportHeight = 0,
 	currentViewportWidth = 0,
 	shouldResetMouse = false;
@@ -47,6 +48,7 @@ export async function reset(opts = {}) {
 		lang: DEFAULT_LANG,
 		mathjax: {},
 		rtl: !!opts.lang?.startsWith('ar'),
+		theme: 'light',
 		pagePadding: DEFAULT_PAGE_PADDING,
 		media: DEFAULT_MEDIA
 	};
@@ -89,6 +91,13 @@ export async function reset(opts = {}) {
 		currentRtl = opts.rtl;
 	}
 
+	if (opts.theme !== currentTheme) {
+		let theme = ['light', 'dark'].includes(opts.theme) ? opts.theme : 'light';
+		document.documentElement.dataset.theme = theme;
+		awaitNextFrame = true;
+		currentTheme = theme;
+	}
+
 	opts.lang ??= '';
 	if (documentLocaleSettings.language !== opts.lang) {
 		document.documentElement.lang = opts.lang;

src/server/wtr-config.js

@@ -118,7 +118,7 @@ export class WTRConfig {
 								font-size: 20px;
 							}
 							body {
-								background-color: #ffffff;
+								background-color: var(--d2l-color-background-base);
 								color: var(--d2l-color-ferrite, #202122);
 								font-family: 'Lato', sans-serif;
 								letter-spacing: 0.01rem;