Convert to ESM

src/wait.ts

@@ -1,13 +1,12 @@
 /**
- * Wait for a number of milliseconds.
+ * Waits for a number of milliseconds.
+ *
  * @param milliseconds The number of milliseconds to wait.
- * @returns {Promise<string>} Resolves with 'done!' after the wait is over.
+ * @returns Resolves with 'done!' after the wait is over.
  */
 export async function wait(milliseconds: number): Promise<string> {
-  return new Promise(resolve => {
-    if (isNaN(milliseconds)) {
-      throw new Error('milliseconds not a number')
-    }
+  return new Promise((resolve) => {
+    if (isNaN(milliseconds)) throw new Error('milliseconds is not a number')
 
     setTimeout(() => resolve('done!'), milliseconds)
   })