fix(material-experimental/theming): Add more tests for M3 theme tokens (#28561)

Additional tests that help ensure our M3 theme conforms to the following
rules:
- Does not add any additional selector specificity
- Emits only CSS variable definitions
- Emits each token for one and only one theme dimension

Also fixes several existing bugs that were discovered by the new tests.

Author: mmalerba

src/material-experimental/theming/_custom-tokens.scss

@@ -70,15 +70,15 @@
     small-size-container-size: _hardcode(6px, $exclude-hardcoded),
     container-padding: _hardcode(0 4px, $exclude-hardcoded),
     small-size-container-padding: _hardcode(0, $exclude-hardcoded),
-    container-offset: -12px 0,
-    small-size-container-offset: -6px 0,
-    container-overlap-offset: -12px,
-    small-size-container-overlap-offset: -6px,
+    container-offset: _hardcode(-12px 0, $exclude-hardcoded),
+    small-size-container-offset: _hardcode(-6px 0, $exclude-hardcoded),
+    container-overlap-offset: _hardcode(-12px, $exclude-hardcoded),
+    small-size-container-overlap-offset: _hardcode(-6px, $exclude-hardcoded),
 
     // This size isn't in the M3 spec so we emit the same values as for `medium`.
     large-size-container-size: _hardcode(16px, $exclude-hardcoded),
-    large-size-container-offset: -12px 0,
-    large-size-container-overlap-offset: -12px,
+    large-size-container-offset: _hardcode(-12px 0, $exclude-hardcoded),
+    large-size-container-overlap-offset: _hardcode(-12px, $exclude-hardcoded),
     large-size-text-size: map.get($systems, md-sys-typescale, label-small-size),
     large-size-container-padding: _hardcode(0 4px, $exclude-hardcoded),
     legacy-large-size-container-size: _hardcode(unset, $exclude-hardcoded),
@@ -423,7 +423,7 @@
   @return (
     container-max-width: _hardcode(560px, $exclude-hardcoded),
     container-small-max-width: _hardcode(calc(100vw - 32px), $exclude-hardcoded),
-    container-min-width: _harcode(280px, $exclude-hardcoded),
+    container-min-width: _hardcode(280px, $exclude-hardcoded),
     actions-alignment: _hardcode(flex-end, $exclude-hardcoded),
     content-padding: _hardcode(20px 24px, $exclude-hardcoded),
     with-actions-content-padding: _hardcode(20px 24px 0, $exclude-hardcoded),
@@ -1169,28 +1169,28 @@
 /// @param {Boolean} $exclude-hardcoded Whether to exclude hardcoded token values
 /// @return {Map} A set of custom tokens for the mat-slide-toggle
 @function switch($systems, $exclude-hardcoded) {
-  @return ((
-    unselected-handle-size: 16px,
-    selected-handle-size: 24px,
-    with-icon-handle-size: 24px,
-    pressed-handle-size: 28px,
-    selected-handle-horizontal-margin: 0 24px,
-    selected-with-icon-handle-horizontal-margin: 0 24px,
-    selected-pressed-handle-horizontal-margin: 0 22px,
-    unselected-handle-horizontal-margin: 0 8px,
-    unselected-with-icon-handle-horizontal-margin: 0 4px,
-    unselected-pressed-handle-horizontal-margin: 0 2px,
+  @return (
+    unselected-handle-size: _hardcode(16px, $exclude-hardcoded),
+    selected-handle-size: _hardcode(24px, $exclude-hardcoded),
+    with-icon-handle-size: _hardcode(24px, $exclude-hardcoded),
+    pressed-handle-size: _hardcode(28px, $exclude-hardcoded),
+    selected-handle-horizontal-margin: _hardcode(0 24px, $exclude-hardcoded),
+    selected-with-icon-handle-horizontal-margin: _hardcode(0 24px, $exclude-hardcoded),
+    selected-pressed-handle-horizontal-margin: _hardcode(0 22px, $exclude-hardcoded),
+    unselected-handle-horizontal-margin: _hardcode(0 8px, $exclude-hardcoded),
+    unselected-with-icon-handle-horizontal-margin: _hardcode(0 4px, $exclude-hardcoded),
+    unselected-pressed-handle-horizontal-margin: _hardcode(0 2px, $exclude-hardcoded),
     // The hidden and visible track represent whichever track is visible or
     // hidden in the ui. This could be the .mdc-switch__track :before or
     // :after depending on whether the switch is selected or unselected.
     //
     // The m2 slide-toggle uses transforms to hide & show the tracks while
     // the m3 slide-toggle uses opacity.
-    visible-track-opacity: 1,
-    hidden-track-opacity: 0,
-    visible-track-transition: opacity 75ms,
-    hidden-track-transition: opacity 75ms,
-  ), ());
+    visible-track-opacity: _hardcode(1, $exclude-hardcoded),
+    hidden-track-opacity: _hardcode(0, $exclude-hardcoded),
+    visible-track-transition: _hardcode(opacity 75ms, $exclude-hardcoded),
+    hidden-track-transition: _hardcode(opacity 75ms, $exclude-hardcoded),
+  );
 }
 
 /// Generates custom tokens for the mat-snack-bar.
@@ -1291,7 +1291,7 @@
     _generate-typography-tokens($systems, label-text, title-small),
     (
       divider-color: map.get($systems, md-sys-color, surface-variant),
-      divider-height: 1px,
+      divider-height: _hardcode(1px, $exclude-hardcoded),
       disabled-ripple-color: null, // TODO(mmalerba): Figure out correct value.
       pagination-icon-color: map.get($systems, md-sys-color, on-surface),
       inactive-label-text-color: map.get($systems, md-sys-color, on-surface),

src/material-experimental/theming/_m3-density.scss

@@ -118,6 +118,8 @@ $_density-tokens: (
   (mat, minimal-pseudo-checkbox): (),
   (mat, paginator): (
     container-size: (56px, 52px, 48px, 40px),
+    form-field-container-height: (40px, 40px, 40px, 40px, 40px, 36px),
+    form-field-container-vertical-padding: (8px, 8px, 8px, 8px, 8px, 6px),
   ),
   (mat, radio): (
     touch-target-display: (block, block, none, none),

src/material-experimental/theming/_m3-tokens.scss

@@ -446,7 +446,7 @@
     headline-weight: subhead-weight,
   ));
 
-  @if (map.has-key($tokens, container-elevation)) {
+  @if map.get($tokens, container-elevation) != null {
     $tokens: map.merge($tokens, (
       // The spec has the dialog at an elevation of 3 which is consistent with the current
       // version of the tokens (0_161), however both the designs and MDC's implementation
@@ -472,7 +472,10 @@
   // However, this interferes with the use case of placing a list on other components. For example,
   // the bottom sheet's container color is `md.sys.color.surface-container-low`. Instead, allow the
   // list to just display the colors for its background.
-  @return map.set($tokens, list-item-container-color, transparent);
+  @if map.get($tokens, list-item-container-color) != null {
+    $tokens: map.set($tokens, list-item-container-color, transparent);
+  }
+  @return $tokens;
 }
 
 /// Generates a set of namespaced tokens for all components.
@@ -976,7 +979,13 @@
     mdc-tokens.md-sys-color-values-light($ref));
   @return _generate-tokens(map.merge($ref, (
     md-sys-color: $sys-color,
+    // Because the elevation values are always combined with color values to create the box shadow,
+    // elevation needs to be part of the color dimension.
     md-sys-elevation: mdc-tokens.md-sys-elevation-values(),
+    // Because the state values are sometimes combined with color values to create rgba colors,
+    // state needs to be part of color dimension.
+    // TODO(mmalerba): If at some point we remove the need for these combined values, we can move
+    //  state to the base dimension.
     md-sys-state: mdc-tokens.md-sys-state-values(),
   )));
 }
@@ -1012,6 +1021,5 @@
   @return _generate-tokens((
     md-sys-motion: mdc-tokens.md-sys-motion-values(),
     md-sys-shape: mdc-tokens.md-sys-shape-values(),
-    md-sys-state: mdc-tokens.md-sys-state-values(),
   ), $include-non-systemized: true);
 }

src/material/button/_button-theme.scss

@@ -112,7 +112,7 @@
 /// @param {Map} $theme The theme to generate base styles for.
 @mixin base($theme) {
   @if inspection.get-theme-version($theme) == 1 {
-    @include theme-from-tokens(inspection.get-theme-tokens($theme, base));
+    @include _theme-from-tokens(inspection.get-theme-tokens($theme, base));
   }
   @else {
     @include sass-utils.current-selector-or-root() {

src/material/core/theming/_inspection.scss

@@ -260,6 +260,7 @@ $_typography-properties: (font, font-family, line-height, font-size, letter-spac
       }
       @else if $system == density {
         $theme: map.deep-remove($theme, $_internals, density-scale);
+        $theme: map.deep-remove($theme, $_internals, density-tokens);
       }
     }
     @return $theme;

src/material/core/theming/tests/m3-theme.spec.ts

@@ -44,9 +44,27 @@ function transpile(content: string) {
   ).css.toString();
 }
 
+function union<T>(...sets: Set<T>[]): Set<T> {
+  return new Set(sets.flatMap(s => [...s]));
+}
+
+function intersection<T>(set: Set<T>, ...sets: Set<T>[]): Set<T> {
+  return new Set([...set].filter(i => sets.every(s => s.has(i))));
+}
+
 describe('M3 theme', () => {
   it('should emit all styles under the given selector', () => {
-    const root = parse(transpile(`html { @include mat.all-component-themes($theme); }`));
+    const root = parse(
+      transpile(`
+      html {
+        @include mat.all-component-themes($theme);
+        @include mat.all-component-bases($theme);
+        @include mat.all-component-colors($theme);
+        @include mat.all-component-typographies($theme);
+        @include mat.all-component-densities($theme);
+      }
+    `),
+    );
     const selectors: string[] = [];
     root.walkRules(rule => {
       selectors.push(rule.selector);
@@ -64,4 +82,41 @@ describe('M3 theme', () => {
     });
     expect(nonVarProps).toEqual([]);
   });
+
+  it('should not have overlapping tokens between theme dimensions', () => {
+    const css = transpile(`
+        $theme: matx.define-theme();
+        base {
+          @include mat.all-component-bases($theme);
+        }
+        color {
+          @include mat.all-component-colors($theme);
+        }
+        typography {
+          @include mat.all-component-typographies($theme);
+        }
+        density {
+          @include mat.all-component-densities($theme);
+        }
+    `);
+    const root = parse(css);
+    const propSets: {[key: string]: Set<string>} = {};
+    root.walkRules(rule => {
+      rule.walkDecls(decl => {
+        propSets[rule.selector] = propSets[rule.selector] || new Set();
+        propSets[rule.selector].add(decl.prop);
+      });
+    });
+    let overlap = new Set();
+    for (const [dimension1, props1] of Object.entries(propSets)) {
+      for (const [dimension2, props2] of Object.entries(propSets)) {
+        if (dimension1 !== dimension2) {
+          overlap = union(overlap, intersection(props1, props2));
+        }
+      }
+    }
+    expect([...overlap])
+      .withContext('Did you forget to wrap these in `_hardcode()`?')
+      .toEqual([]);
+  });
 });

src/material/core/theming/tests/theming-inspection-api.spec.ts

@@ -466,5 +466,14 @@ describe('theming inspection api', () => {
         `),
       ).toThrowError(/Density information is not available on this theme/);
     });
+
+    it('should not emit styles for removed theme dimensions', () => {
+      const css = transpile(`
+        $theme: mat.theme-remove(matx.define-theme(), base, color, typography, density);
+        div {
+          @include mat.all-component-themes($theme);
+        }`);
+      expect(css).toBe('');
+    });
   });
 });

src/material/core/tokens/m2/mat/_paginator.scss

@@ -1,4 +1,7 @@
+@use 'sass:math';
 @use 'sass:map';
+@use '@material/textfield' as mdc-textfield;
+@use '@material/density' as mdc-density;
 @use '../../token-utils';
 @use '../../../theming/theming';
 @use '../../../theming/inspection';
@@ -39,16 +42,33 @@ $prefix: (mat, paginator);
 
 // Tokens that can be configured through Angular Material's density theming API.
 @function get-density-tokens($theme) {
-  $density-scale: theming.clamp-density(inspection.get-theme-density($theme), -3);
+  $density-scale: theming.clamp-density(inspection.get-theme-density($theme), -5);
   $size-scale: (
     0: 56px,
     -1: 52px,
     -2: 48px,
     -3: 40px,
+    -4: 40px,
+    -5: 40px,
   );
+  $form-field-density-scale: if($density-scale > -4, -4, $density-scale);
+  $form-field-height: mdc-density.prop-value(
+    $density-config: mdc-textfield.$density-config,
+    $density-scale: $form-field-density-scale,
+    $property-name: height,
+  );
+  // We computed the desired height of the form-field using the density configuration. The
+  // spec only describes vertical spacing/alignment in non-dense mode. This means that we
+  // cannot update the spacing to explicit numbers based on the density scale. Instead, we
+  // determine the height reduction and equally subtract it from the default `top` and `bottom`
+  // padding that is provided by the Material Design specification.
+  $form-field-vertical-deduction: math.div(mdc-textfield.$height - $form-field-height, 2);
+  $form-field-vertical-padding: 16px - $form-field-vertical-deduction;
 
   @return (
-    container-size: map.get($size-scale, $density-scale)
+    container-size: map.get($size-scale, $density-scale),
+    form-field-container-height: $form-field-height,
+    form-field-container-vertical-padding: $form-field-vertical-padding,
   );
 }
 

src/material/core/typography/_all-typography.scss

@@ -51,7 +51,12 @@
   // mixin that is transitively loaded by the `all-theme` file, imports `all-typography` which
   // would then load `all-theme` again. This ultimately results a circular dependency.
   @include badge-theme.typography($theme);
-  @include typography.typography-hierarchy($theme);
+  // Historically the typography hierarchy styles were included as part of this. We maintain this
+  // behavior for M2, but from M3 forward this is not included and should be explicitly @included
+  // by the user if desired.
+  @if (inspection.get-theme-version($theme) < 1) {
+    @include typography.typography-hierarchy($theme);
+  }
   @include bottom-sheet-theme.typography($theme);
   @include button-toggle-theme.typography($theme);
   @include divider-theme.typography($theme);

src/material/paginator/_paginator-theme.scss

@@ -1,7 +1,6 @@
 @use 'sass:map';
 @use 'sass:meta';
 @use '../core/tokens/m2/mat/paginator' as tokens-mat-paginator;
-@use '../form-field/form-field-theme';
 @use '../core/style/sass-utils';
 @use '../core/typography/typography';
 @use '../core/theming/theming';
@@ -53,12 +52,6 @@
         tokens-mat-paginator.get-density-tokens($theme));
     }
   }
-
-  // We need the form field to be narrower in order to fit into the paginator,
-  // so we set its density to be -4 or denser.
-  .mat-mdc-paginator {
-    @include form-field-theme.density((density: $form-field-density));
-  }
 }
 
 @mixin theme($theme) {