fix: CJS interop rollup option for handling default exports

.changeset/fuzzy-shoes-hug.md

@@ -0,0 +1,5 @@
+---
+'@tokens-studio/sd-transforms': patch
+---
+
+Use Rollup output.interop for CJS output, to properly handle default exports in our CJS external dependencies.

package.json

@@ -52,7 +52,7 @@
   "devDependencies": {
     "@changesets/cli": "^2.26.0",
     "@esm-bundle/chai": "^4.3.4-fix.0",
-    "@rollup/plugin-commonjs": "^24.0.1",
+    "@rollup/plugin-commonjs": "^24.1.0",
     "@rollup/plugin-node-resolve": "^15.0.1",
     "@rollup/plugin-typescript": "^11.0.0",
     "@typescript-eslint/eslint-plugin": "^5.54.0",

rollup/cjs.config.mjs

@@ -23,6 +23,10 @@ export default {
     format: 'cjs',
     preserveModules: true,
     entryFileNames: '[name].cjs',
+    // Ensures that CJS default exports are imported properly (based on __esModule)
+    // If needed, can switch to 'compat' which checks for .default prop on the default export instead
+    // see https://rollupjs.org/configuration-options/#output-interop
+    interop: 'auto',
   },
   plugins: [nodeResolve(), typescript({ tsconfig: 'tsconfig.build.json', declaration: false })],
 };