FIX: Update GetFileInfo logic to correctly handle directories

Author: HyunWooZZ

cpp/src/arrow/filesystem/gcsfs.cc

@@ -354,14 +354,15 @@ class GcsFileSystem::Impl {
     std::string canonical = internal::EnsureTrailingSlash(path.object);
     auto list_result = client_.ListObjects(path.bucket, gcs::Prefix(canonical));
 
-    // Check that the result is valid before determining whether the list is empty.
-    auto it = list_result.begin();
-    if (it != list_result.end() && *it) {
-      // If there is at least one result it indicates this is a directory (at
-      // least one object exists that starts with "path/")
+    for (auto&& object_metadata : list_result) {
+      if (!object_metadata) {
+        continue;
+      }
+      // If there is at least one valid result, it indicates this is a
+      // directory (at least one object exists that starts with "path/")
       return FileInfo(path.full_path, FileType::Directory);
     }
-    // Return the original not-found info if there was no match.
+    // Return the original not-found info if there was no valid result.
     return info;
   }
 

cpp/src/arrow/filesystem/gcsfs_test.cc

@@ -644,22 +644,12 @@ TEST_F(GcsIntegrationTest, GetFileInfo) {
 
   // check parent directories are recognized as directories.
   AssertFileInfo(fs.get(), PreexistingBucketPath() + "dir/", FileType::Directory);
-  AssertFileInfo(fs.get(), PreexistingBucketPath() + "dir/foo/", FileType::Directory);
-}
-
-TEST_F(GcsIntegrationTest, GetFileInfoWithoutPermission) {
-  auto options = GcsOptions::Defaults();
-  // Test with real GCS.
-  ASSERT_OK_AND_ASSIGN(auto fs, GcsFileSystem::Make(options));
-  // Without permission, always File typs is FileType::NotFound.
-  constexpr auto kTextFileName = "dir/foo/bar.txt";
 
-  // check this is the File without permission.
-  AssertFileInfo(fs.get(), PreexistingBucketPath() + kTextFileName, FileType::NotFound);
-
-  // check this is the directory without permission.
-  AssertFileInfo(fs.get(), PreexistingBucketPath() + "dir/", FileType::NotFound);
-  AssertFileInfo(fs.get(), PreexistingBucketPath() + "dir/foo/", FileType::NotFound);
+  // check not exists.
+  AssertFileInfo(fs.get(), PreexistingBucketPath() + "dir/foo/unexpected_dir/",
+                 FileType::NotFound);
+  AssertFileInfo(fs.get(), PreexistingBucketPath() + "dir/foo/not_bar.txt",
+                 FileType::NotFound);
 }
 
 TEST_F(GcsIntegrationTest, GetFileInfoObjectWithNestedStructure) {