Refactor View.prototype.resolve to improve readability and efficiency

- Simplified logic for resolving file paths.
- Used optional chaining for cleaner code.
- Maintained functionality while enhancing clarity.
- Updated JSDoc to specify the return type: {string|undefined}.

lib/view.js

@@ -163,27 +163,19 @@ View.prototype.render = function render(options, callback) {
  *
  * @param {string} dir
  * @param {string} file
+ * @return {string|undefined}
  * @private
  */
-
 View.prototype.resolve = function resolve(dir, file) {
-  var ext = this.ext;
-
-  // <path>.<ext>
-  var path = join(dir, file);
-  var stat = tryStat(path);
+  const ext = this.ext;
 
-  if (stat && stat.isFile()) {
-    return path;
-  }
+  let path = join(dir, file);
+  if (tryStat(path)?.isFile()) return path;
 
-  // <path>/index.<ext>
-  path = join(dir, basename(file, ext), 'index' + ext);
-  stat = tryStat(path);
+  path = join(dir, basename(file, ext), `index${ext}`);
+  if (tryStat(path)?.isFile()) return path;
 
-  if (stat && stat.isFile()) {
-    return path;
-  }
+  return undefined;
 };
 
 /**