refactor(material/theming): make batch-create-token-values more flexible (#28897)

* Refactor token-utils.batch-create-token-values to allow us to pass in as many token maps as
  we want. This is change is relevant for components like the button which would want to pass
  in token maps for each button variant.

Author: wagnermaciel

src/material/checkbox/_checkbox-theme.scss

@@ -97,10 +97,8 @@
 @mixin overrides($tokens: ()) {
   @include token-utils.batch-create-token-values(
     $tokens,
-    $mat-prefix: tokens-mat-checkbox.$prefix,
-    $mdc-prefix: tokens-mdc-checkbox.$prefix,
-    $mat-tokens: tokens-mat-checkbox.get-token-slots(),
-    $mdc-tokens: tokens-mdc-checkbox.get-token-slots(),
+    (prefix: tokens-mat-checkbox.$prefix, tokens: tokens-mat-checkbox.get-token-slots()),
+    (prefix: tokens-mdc-checkbox.$prefix, tokens: tokens-mdc-checkbox.get-token-slots()),
   );
 }
 

src/material/core/tokens/_token-utils.scss

@@ -214,58 +214,44 @@ $_component-prefix: null;
   @return if($emit-overrides-only, $overrides, map.merge($values, $overrides));
 }
 
-/// Emits new token values for the given tokens.
-/// Verifies that the tokens passed in are valid tokens.
+/// Emits new token values for the given token overrides.
+/// Verifies that the overrides passed in are valid tokens.
 /// New token values are emitted under the current selector or root.
-@mixin batch-create-token-values(
-  $tokens: (),
-  $mat-prefix: '',
-  $mdc-prefix: '',
-  $mat-tokens: (),
-  $mdc-tokens: ()
-) {
-  $custom-mat-tokens: ();
-  $custom-mdc-tokens: ();
+@mixin batch-create-token-values($overrides: (), $token-maps...) {
+  @include _validate-token-overrides($overrides, $token-maps);
 
-  $mat-token-names: map.keys($mat-tokens);
-  $mdc-token-names: map.keys($mdc-tokens);
-  $valid-token-names: _get-valid-token-names($mat-tokens, $mdc-tokens);
+  @each $token-map in $token-maps {
+    $prefix: map.get($token-map, prefix);
+    $tokens: map.get($token-map, tokens);
 
-  @each $name, $value in $tokens {
-    $is-mat-token: list.index($mat-token-names, $name) != null;
-    $is-mdc-token: list.index($mdc-token-names, $name) != null;
+    @each $name, $value in $tokens {
+      $tokens: map.set($tokens, $name, map.get($overrides, $name));
+    }
 
-    @if ($is-mat-token) {
-      $custom-mat-tokens: map.set($custom-mat-tokens, $name, $value);
+    @include sass-utils.current-selector-or-root() {
+      @include create-token-values($prefix, $tokens);
     }
+  }
+}
+
+/// Verifies that the token overrides exist and are used in one of the given token maps.
+@mixin _validate-token-overrides($overrides: (), $token-maps) {
+  $valid-token-names: ();
 
-    @if ($is-mdc-token) {
-      $custom-mdc-tokens: map.set($custom-mdc-tokens, $name, $value);
+  @each $token-map in $token-maps {
+    @each $name, $value in map.get($token-map, tokens) {
+      @if ($value != null and list.index($valid-token-names, $name) == null) {
+        $valid-token-names: list.append($valid-token-names, $name);
+      }
     }
+  }
 
+  @each $name in map.keys($overrides) {
     @if (list.index($valid-token-names, $name) == null) {
       @error (
         'Invalid token: "' + $name + '"'
         'Valid tokens include: ' $valid-token-names
       );
     }
   }
-
-  @include sass-utils.current-selector-or-root() {
-    @include create-token-values($mat-prefix, $custom-mat-tokens);
-    @include create-token-values($mdc-prefix, $custom-mdc-tokens);
-  }
-}
-
-/// Returns the union of token names whose values are not null.
-@function _get-valid-token-names($mat-tokens, $mdc-tokens) {
-  $mat-and-mdc-tokens: map.merge($mat-tokens, $mdc-tokens);
-
-  @each $name, $value in $mat-and-mdc-tokens {
-    @if ($value == null) {
-      $mat-and-mdc-tokens: map.remove($mat-and-mdc-tokens, $name);
-    }
-  }
-
-  @return map.keys($mat-and-mdc-tokens);
 }