chore: add script to generate Sass token metadata files

PiperOrigin-RevId: 895583199

Author: asyncliz

.gitignore

@@ -5,6 +5,7 @@ node_modules
 *.css
 *.cssresult.ts
 *-styles.ts
+tokens/versions/**/*-meta.scss
 *.map
 *.d.ts
 !types/*.d.ts

package.json

@@ -158,8 +158,20 @@
         "**/*.css",
         "**/*.css.map",
         "!catalog/"
+      ],
+      "dependencies": [
+        "build:sass:generate"
       ]
     },
+    "build:sass:generate": {
+      "command": "find tokens/versions/ -type f -name '_md-*.scss' ! -name '*-meta.scss' -print0 | xargs -0 node scripts/generate-sass-token-meta.js",
+      "files": [
+        "tokens/versions/**/_md-*.scss",
+        "!tokens/versions/**/*-meta.scss"
+      ],
+      "output": ["tokens/versions/**/*-meta.scss"],
+      "dependencies": ["build:scripts"]
+    },
     "test": {
       "command": "wtr",
       "dependencies": [

scripts/generate-sass-token-meta.ts

@@ -0,0 +1,77 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/** @fileoverview Generates tokens/versions/latest/_md-{name}-meta.scss files. */
+
+import * as fs from 'fs';
+import * as util from 'util';
+function generateMetaFile(inputFilePath: string, outputFilePath: string) {
+  const content = fs.readFileSync(inputFilePath, {encoding: 'utf8'});
+  const metaVars: string[] = [];
+
+  // Regex to match variable declarations: $name: value;
+  const varRegex = /^\s*\$([\w-]+)\s*:\s*([^;]+);/gm;
+  let match: RegExpExecArray | null;
+  while ((match = varRegex.exec(content)) !== null) {
+    const name = match[1];
+    let value = match[2].trim();
+
+    // Resolve the value to a CSS var() if it references another token.
+    // (e.g. md-sys-color.$primary or $primary)
+    const refMatch = value.match(/^(?:([\w-]+)\.)?\$([\w-]+)$/);
+    if (refMatch) {
+      const refModule = refMatch[1] || null;
+      const refToken = refMatch[2];
+      value = `var(--${refModule ? `${refModule}-` : ''}${refToken})`;
+    }
+
+    metaVars.push(`$${name}--resolved: ${value};`);
+  }
+
+  fs.writeFileSync(
+    outputFilePath,
+    `//
+// Copyright 2026 Google LLC
+// SPDX-License-Identifier: Apache-2.0
+//
+// Auto-generated token metadata.
+${metaVars.join('\n')}
+`,
+  );
+}
+
+const {values, positionals} = util.parseArgs({
+  allowPositionals: true,
+  options: {
+    outputs: {type: 'string'},
+  },
+});
+
+const inputs: string[] = positionals;
+const outputs: string[] = [];
+
+if (inputs.length === 0) {
+  throw new Error(
+    `Usage: node generate-sass-token-meta.js <input.scss>... [--outputs "out1-meta.scss out2-meta.scss"]`,
+  );
+}
+if (values.outputs) {
+  outputs.push(...values.outputs.trim().split(/\s+/).filter(Boolean));
+}
+if (outputs.length === 0) {
+  for (const input of inputs) {
+    outputs.push(input.replace('.scss', '-meta.scss'));
+  }
+}
+if (inputs.length !== outputs.length) {
+  throw new Error(
+    `Inputs and outputs length mismatch: ${inputs.length} vs ${outputs.length}`,
+  );
+}
+
+for (let i = 0; i < inputs.length; i++) {
+  generateMetaFile(inputs[i], outputs[i]);
+}