fix #2115: support @font-palette-values

Author: evanw

CHANGELOG.md

@@ -1,5 +1,22 @@
 # Changelog
 
+## Unreleased
+
+* Add support for some new CSS rules ([#2115](https://github.com/evanw/esbuild/issues/2115))
+
+    This release adds support for [`@font-palette-values`](https://drafts.csswg.org/css-fonts-4/#font-palette-values):
+
+    ```css
+    /* Original code */
+    @font-palette-values Foo { base-palette: 1; }
+
+    /* Old output (with --minify) */
+    @font-palette-values Foo{base-palette: 1;}
+
+    /* New output (with --minify) */
+    @font-palette-values Foo{base-palette:1}
+    ```
+
 ## 0.14.27
 
 * Avoid generating an enumerable `default` import for CommonJS files in Babel mode ([#2097](https://github.com/evanw/esbuild/issues/2097))

internal/css_parser/css_parser.go

@@ -681,6 +681,9 @@ var specialAtRules = map[string]atRuleKind{
 
 	// Reference: https://drafts.csswg.org/css-nesting-1/
 	"nest": atRuleDeclarations,
+
+	// Reference: https://drafts.csswg.org/css-fonts-4/#font-palette-values
+	"font-palette-values": atRuleDeclarations,
 }
 
 type atRuleValidity uint8

internal/css_parser/css_parser_test.go

@@ -849,6 +849,23 @@ func TestAtRule(t *testing.T) {
     content: "rb";
   }
 }
+`)
+
+	// https://drafts.csswg.org/css-fonts-4/#font-palette-values
+	expectPrinted(t, `
+		@font-palette-values Augusta {
+			font-family: Handover Sans;
+			base-palette: 3;
+			override-colors: 1 rgb(43, 12, 9), 2 #000, 3 var(--highlight)
+		}
+	`, `@font-palette-values Augusta {
+  font-family: Handover Sans;
+  base-palette: 3;
+  override-colors:
+    1 rgb(43, 12, 9),
+    2 #000,
+    3 var(--highlight);
+}
 `)
 }