Switched to type: module.

scripts/format-lang.js

@@ -0,0 +1,36 @@
+import path from 'node:path';
+import fs from 'fs-extra';
+import del from 'del';
+import prettier from 'prettier';
+import { createRequire } from 'module';
+
+const require = createRequire(import.meta.url);
+const src = path.resolve(process.cwd(), 'src/lang');
+const dest = path.resolve(process.cwd(), 'build/messages');
+const files = fs.readdirSync(src);
+
+del.sync([path.join(dest)]);
+
+/*
+This script takes the files from the `lang` folder and formats them into
+the format that format-js expects.
+ */
+async function run() {
+  await fs.ensureDir(dest);
+
+  files.forEach(file => {
+    const lang = require(path.resolve(process.cwd()`src/lang/${file}`));
+    const keys = Object.keys(lang).sort();
+
+    const formatted = keys.reduce((obj, key) => {
+      obj[key] = { defaultMessage: lang[key] };
+      return obj;
+    }, {});
+
+    const json = prettier.format(JSON.stringify(formatted), { parser: 'json' });
+
+    fs.writeFileSync(path.resolve(dest, file), json);
+  });
+}
+
+run();