feat(tokens): create variables fallbacks based on its alias token (#30404)

Issue number:  internal

---------

<!-- Please do not submit updates to dependencies unless it fixes an
issue. -->

<!-- Please try to limit your pull request to one type (bugfix, feature,
etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

Currently, even if a token used an alias token as its value, when we're
generating the variables we wouldn't respect this connection and were
simply adding the fixed final value.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- Now when a token uses an alias token, we keep that relationship by
making sure the alias variable is used as fallback.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!--
  If this introduces a breaking change:
1. Describe the impact and migration path for existing applications
below.
  2. Update the BREAKING.md file with the breaking change.
3. Add "BREAKING CHANGE: [...]" to the commit description when merging.
See
https://github.com/ionic-team/ionic-framework/blob/main/docs/CONTRIBUTING.md#footer
for more information.
-->


## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

Author: BenOsodrac

core/scripts/tokens/index.js

@@ -43,12 +43,25 @@
 
       console.log('Generating SCSS variables...');
 
-      // Separate typography tokens from the rest
-      const typographyProperties = dictionary.allTokens.filter((prop) => prop.$type === 'typography');
-      const otherProperties = dictionary.allTokens.filter((prop) => prop.$type !== 'typography');
-
-      // Make sure the reused scss variables are defined first, to avoid compilation errors
-      const sortedProperties = [...otherProperties, ...typographyProperties];
+      const primitiveProperties = dictionary.allTokens.filter((prop) => prop.path[0] === 'primitives');
+      const scaleProperties = dictionary.allTokens.filter((prop) => prop.path[0] === 'scale');
+      const borderProperties = dictionary.allTokens.filter((prop) => prop.path[0] === 'border');
+      const semanticsProperties = dictionary.allTokens.filter((prop) => prop.path[0] === 'semantics');
+      const nonPrimitiveScaleBorderSemanticsProperties = dictionary.allTokens.filter(
+        (prop) => !['primitives', 'scale', 'border', 'semantics'].includes(prop.path[0])
+      );
+      const typographyProperties = nonPrimitiveScaleBorderSemanticsProperties.filter((prop) => prop.$type === 'typography');
+      const otherProperties = nonPrimitiveScaleBorderSemanticsProperties.filter((prop) => prop.$type !== 'typography');
+      
+      // Order: primitives → semantics → scale → border → other → typography
+      const sortedProperties = [
+        ...primitiveProperties,
+        ...semanticsProperties,
+        ...scaleProperties,
+        ...borderProperties,
+        ...otherProperties,
+        ...typographyProperties
+      ];
 
       const prefixedVariables = sortedProperties.map((prop) => {
         // Remove consecutive repeated words from the token name, like border-border-color

core/scripts/tokens/utils.js

@@ -48,6 +48,19 @@ function removeConsecutiveRepeatedWords(str) {
     return str.replace(/(\b\w+\b)(-\1)+/g, '$1');
 }
 
+// Generates a reference variable for an alias token type
+// (e.g., $ion-border-default: var(--ion-border-default, #d5d5d5) → $ion-border-default: var(--ion-border-default, $ion-primitives-neutral-400))
+function getAliasReferenceVariable(prop) {
+  if (typeof prop.$value === 'string' && prop.$value.startsWith('{') && prop.$value.endsWith('}')) {
+    // Remove curly braces and replace dots with dashes
+    let ref = prop.$value.slice(1, -1).replace(/\./g, '-');
+    // Remove consecutive repeated words (e.g., border-border-radius-0 → border-radius-0)
+    ref = removeConsecutiveRepeatedWords(ref);
+    return `$${variablesPrefix}-${ref}`;
+  }
+  return null;
+}
+
 // Generates a valid box-shadow value from a shadow Design Token structure
 function generateShadowValue(prop, propName) {
   const cssShadow = prop.$value.map(shadow => {
@@ -80,17 +93,25 @@ function generateFontFamilyValue(prop, propName, variableType = 'css') {
 
 // Generates a final value, based if the Design Token is of type color or not
 function generateValue(prop, propName) {
-  const rgb = hexToRgb(prop.$value);
+  // Use the original value to detect aliases
+  const aliasVar = getAliasReferenceVariable({ $value: prop.original.$value });
 
-  let rgbDeclaration = '';
+  // Always generate the main variable
+  let mainValue;
+  if (aliasVar) {
+    mainValue = `$${variablesPrefix}-${propName}: var(--${variablesPrefix}-${propName}, ${aliasVar});`;
+  } else {
+    mainValue = `$${variablesPrefix}-${propName}: var(--${variablesPrefix}-${propName}, ${prop.$value});`;
+  }
 
+  // Always generate the -rgb variable if it's a color
+  const rgb = hexToRgb(prop.$value);
+  let rgbDeclaration = '';
   if (rgb) {
-    // If the token is color, also add a rgb variable using the same color
     rgbDeclaration = `\n$${variablesPrefix}-${propName}-rgb: var(--${variablesPrefix}-${propName}-rgb, ${rgb.r}, ${rgb.g}, ${rgb.b});`;
-    prop.value = getRgbaValue(prop.$value);
   }
 
-  return `$${variablesPrefix}-${propName}: var(--${variablesPrefix}-${propName}, ${prop.$value});${rgbDeclaration}`;
+  return `${mainValue}${rgbDeclaration}`;
 }
 
 // Generates a typography based css utility-class or scss variable from a typography token structure
@@ -287,6 +308,7 @@ module.exports = {
     generateFontFamilyValue,
     generateTypographyOutput,
     generateValue,
+    getAliasReferenceVariable,
     setPrefixValue,
     generateRadiusUtilityClasses,
     generateColorUtilityClasses,