fs: make mutating options in Callback readdir() not affect results

Author: LiviaMedeiros

lib/fs.js

@@ -1531,6 +1531,9 @@ function readdir(path, options, callback) {
   }
 
   if (options.recursive) {
+    // Make shallow copy to prevent mutating options from affecting results
+    options = copyObject(options);
+
     readdirRecursive(path, options, callback);
     return;
   }

test/parallel/test-fs-readdir-types.js

@@ -86,6 +86,14 @@ fs.readdir(readdirDir, {
   assertDirents(await direntsPromise);
 })().then(common.mustCall());
 
+{
+  const options = { withFileTypes: true };
+  fs.readdir(readdirDir, options, common.mustSucceed((dirents) => {
+    assertDirents(dirents);
+  }));
+  options.withFileTypes = false;
+}
+
 // Check for correct types when the binding returns unknowns
 const UNKNOWN = constants.UV_DIRENT_UNKNOWN;
 const oldReaddir = binding.readdir;