feat(themes): add ionic theme tokens (#30708)

- Updates the token interface to accept a numeric scale.
- Updates the base tokens to use the new interface.
- Adds tokens for the `ionic` theme based on the existing design tokens.
- Excludes certain keys (`enabled`, `rippleEffect`, `formHighlight`) from the generated CSS variables.
- Removes the `--background` and `--ion-background-color` from the global `ionic` theme overrides, allowing it to use the dark palette.
- Removes the different Ionic colors from the `ionic` theme, ensuring all of the themes use the same named (primary, secondary, etc.) colors.
- Updates the testing script to pull in the tokens based on the theme & palette passed to the URL.
- Adds a new npm script, `build.themes`, to generate the theme files.

---------

Co-authored-by: Brandy Smith <6577830+brandyscarney@users.noreply.github.com>

core/scripts/testing/scripts.js

@@ -1,3 +1,4 @@
+const DEFAULT_THEME = 'md';
 
 (function() {
 
@@ -15,28 +16,15 @@
   }
 
   /**
-   * The term `palette` is used to as a param to match the
-   * Ionic docs, plus here is already a `ionic:theme` query being
-   * used for `md`, `ios`, and `ionic` themes.
-   */
-  const palette = window.location.search.match(/palette=([a-z]+)/);
-  if (palette && palette[1] !== 'light') {
-    const linkTag = document.createElement('link');
-    linkTag.setAttribute('rel', 'stylesheet');
-    linkTag.setAttribute('type', 'text/css');
-    linkTag.setAttribute('href', `/css/palettes/${palette[1]}.always.css`);
-    document.head.appendChild(linkTag);
-  }
-
-  /**
-  * The `ionic` theme uses a different stylesheet than the `iOS` and `md` themes.
-  * This is to ensure that the `ionic` theme is loaded when the `ionic:theme=ionic`
-  * or when the HTML tag has the `theme="ionic"` attribute. This is useful for
-  * the snapshot tests, where the `ionic` theme is not loaded by default.
+  * The `theme` query param is used to load a specific theme.
+  * This can be `ionic`, `ios`, or `md`. Default to `md` for tests.
   */
-  const themeQuery = window.location.search.match(/ionic:theme=([a-z]+)/);
+  const themeQuery = window.location.search.match(/ionic:theme=([a-z0-9]+)/i);
   const themeAttr = document.documentElement.getAttribute('theme');
+  const themeName = themeQuery?.[1] || themeAttr || DEFAULT_THEME;
 
+  // TODO(): Remove this when the tokens are working for all components
+  // and the themes all use the same bundle
   if ((themeQuery && themeQuery[1] === 'ionic') || themeAttr === 'ionic') {
     const ionicThemeLinkTag = document.querySelector('link[href*="css/ionic/bundle.ionic.css"]');
 
@@ -54,6 +42,51 @@
     }
   }
 
+  /**
+   * The `palette` query param is used to load a specific palette
+   * for the theme. This can be `light`, `dark`, `high-contrast`,
+   * or `high-contrast-dark`. Default to `light` for tests.
+   */
+  const paletteQuery = window.location.search.match(/palette=([a-z]+)/);
+  const paletteName = paletteQuery?.[1] || 'light';
+
+  // Load theme tokens if the theme is valid
+  const validThemes = ['ionic', 'ios', 'md'];
+  if (themeName && validThemes.includes(themeName)) {
+    loadThemeTokens(themeName, paletteName);
+  } else if(themeName) {
+    console.warn(
+      `Unsupported theme "${themeName}". Supported themes are: ${validThemes.join(', ')}. Defaulting to ${DEFAULT_THEME}.`
+    );
+  }
+
+  async function loadThemeTokens(themeName, paletteName) {
+    try {
+      // Load the default tokens for the theme
+      const defaultTokens = await import(`/themes/${themeName}/default.tokens.js`);
+      const theme = defaultTokens.defaultTheme;
+
+      // If a specific palette is requested, modify the palette structure
+      // to set the enabled property to 'always'
+      if (paletteName === 'dark' && theme.palette?.dark) {
+        theme.palette.dark.enabled = 'always';
+      }
+
+      // Apply the theme tokens to Ionic config
+      window.Ionic = window.Ionic || {};
+      window.Ionic.config = window.Ionic.config || {};
+      window.Ionic.config.customTheme = theme;
+
+      // Re-apply the global theme
+      if (window.Ionic.config.get && window.Ionic.config.set) {
+        const themeModule = await import('/themes/utils/theme.js');
+        themeModule.applyGlobalTheme(theme);
+      }
+    } catch (error) {
+      console.error(`Failed to load theme tokens for ${themeName}:`, error);
+    }
+  }
+
   window.Ionic = window.Ionic || {};
   window.Ionic.config = window.Ionic.config || {};
 

core/scripts/testing/styles.css

@@ -36,31 +36,21 @@
   --ion-dynamic-font: var(--ion-default-dynamic-font);
 }
 
+/* TODO(FW-6745): Remove this after adding the md tokens */
 :root,
 html,
-html.md.md {
+html.md.md:not(.ionic) {
   --ion-font-family: Roboto, "mdTestingFont", sans-serif;
   font-family: Roboto, "mdTestingFont", sans-serif;
 }
 
+/* TODO(FW-6744): Remove this after adding the ios tokens */
 :root.ios.ios,
 html.ios.ios {
   --ion-font-family: -apple-system, BlinkMacSystemFont, "iosTestingFont", sans-serif;
   font-family: -apple-system, BlinkMacSystemFont, "iosTestingFont", sans-serif;
 }
 
-/* Override above styles for testing scopes */
-:root.ionic,
-:root.ionic.ios,
-:root.ionic.md,
-html.ionic,
-html.ionic.ios,
-html.ionic.md {
-  /* TODO: remove this with the ionic theme updates */
-  --ion-background-color: var(--background);
-  --ion-font-family: initial;
-}
-
 /**
  * Button styles should only be applied
  * to native buttons that are not part of the