refactor(material/theming): add inspection compatibility flag

src/material/_index.scss

@@ -2,7 +2,7 @@
 @forward './core/theming/theming' show define-light-theme, define-dark-theme,
   define-palette, get-contrast-color-from-palette, get-color-from-palette,
   get-color-config, get-typography-config, get-density-config,
-  $theme-ignore-duplication-warnings;
+  $theme-ignore-duplication-warnings, $theme-legacy-inspection-api-compatibility;
 @forward './core/theming/theming' as private-* show private-clamp-density;
 @forward './core/theming/palette' show $red-palette, $pink-palette, $indigo-palette,
   $purple-palette, $deep-purple-palette, $blue-palette, $light-blue-palette, $cyan-palette,

src/material/core/theming/_m2-inspection.scss

@@ -5,10 +5,17 @@
 
 $_typography-properties: (font, font-family, line-height, font-size, letter-spacing, font-weight);
 
+/// Gets the m2-config from the theme.
+@function _get-m2-config($theme) {
+  $internal: map.get($theme, _mat-theming-internals-do-not-access, m2-config);
+  @return $internal or $theme;
+}
+
 /// Gets the type of theme represented by a theme object (light or dark).
 /// @param {Map} $theme The theme
 /// @return {String} The type of theme (either `light` or `dark`).
 @function get-theme-type($theme) {
+  $theme: _get-m2-config($theme);
   @if not theme-has($theme, color) {
     @error 'Color information is not available on this theme.';
   }
@@ -26,6 +33,7 @@ $_typography-properties: (font, font-family, line-height, font-size, letter-spac
 ///   interpreted as a palette name).
 /// @return {Color} The requested theme color.
 @function get-theme-color($theme, $palette-name, $args...) {
+  $theme: _get-m2-config($theme);
   @if not theme-has($theme, color) {
     @error 'Color information is not available on this theme.';
   }
@@ -44,6 +52,7 @@ $_typography-properties: (font, font-family, line-height, font-size, letter-spac
 ///   (font, font-family, font-size, font-weight, line-height, or letter-spacing).
 /// @return {*} The value of the requested font property.
 @function get-theme-typography($theme, $typescale, $property) {
+  $theme: _get-m2-config($theme);
   @if not theme-has($theme, typography) {
     @error 'Typography information is not available on this theme.';
   }
@@ -79,14 +88,20 @@ $_typography-properties: (font, font-family, line-height, font-size, letter-spac
 /// @param {Map} $theme The theme
 /// @return {Number} The density scale.
 @function get-theme-density($theme) {
+  $theme: _get-m2-config($theme);
   @if not theme-has($theme, density) {
     @error 'Density information is not available on this theme.';
   }
   $scale: theming.get-density-config($theme);
   @return theming.clamp-density($scale, -5);
 }
 
+/// Checks whether the theme has information about given theming system.
+/// @param {Map} $theme The theme
+/// @param {String} $system The system to check
+/// @param {Boolean} Whether the theme has information about the system.
 @function theme-has($theme, $system) {
+  $theme: _get-m2-config($theme);
   $theme: theming.private-legacy-get-theme($theme);
   @if $system == base {
     @return true;

src/material/core/theming/_theming.scss

@@ -5,6 +5,8 @@
 @use 'palette';
 @use '../density/private/compatibility';
 
+$theme-legacy-inspection-api-compatibility: true !default;
+
 // Whether duplication warnings should be disabled. Warnings enabled by default.
 $theme-ignore-duplication-warnings: false !default;
 
@@ -544,7 +546,14 @@ $_internals: _mat-theming-internals-do-not-access;
     @return $theme;
   }
   $color: map.get($theme, color);
-  @return map.merge($theme, $color);
+  $m2-config: map.merge($theme, $color);
+  $theme: (
+    _mat-theming-internals-do-not-access: (
+      theme-version: 0,
+      m2-config: $m2-config,
+    )
+  );
+  @return map.merge(if($theme-legacy-inspection-api-compatibility, $m2-config, ()), $theme);
 }
 
 // Gets the theme from the given value that is either already a theme, or a color configuration.