refactor(boot): remove 'for in' workaround

Author: Yaty

packages/boot/src/booters/booter-utils.ts

@@ -44,6 +44,7 @@ export function isClass(target: any): target is Constructor<any> {
  * and then testing each exported member to see if it's a class or not.
  *
  * @param files An array of string of absolute file paths
+ * @param projectRootDir The project root directory
  * @returns {Constructor<{}>[]} An array of Class constructors from a file
  */
 export function loadClassesFromFiles(
@@ -54,10 +55,7 @@ export function loadClassesFromFiles(
   for (const file of files) {
     debug('Loading artifact file %j', path.relative(projectRootDir, file));
     const moduleObj = require(file);
-    // WORKAROUND: use `for in` instead of Object.values().
-    // See https://github.com/nodejs/node/issues/20278
-    for (const k in moduleObj) {
-      const exported = moduleObj[k];
+    for (const [k, exported] of Object.entries(moduleObj)) {
       if (isClass(exported)) {
         debug('  add %s (class %s)', k, exported.name);
         classes.push(exported);