Add test for Unknown sort order

Author: Deepak Majeti

src/parquet/parquet_reader_writer-test.cc

@@ -297,5 +297,29 @@ TYPED_TEST(TestStatistics, MinMax) {
   this->VerifyParquetStats();
 }
 
+// Ensure UNKNOWN sort order is handled properly
+using TestStatisticsFLBA = TestStatistics<FLBAType>;
+
+TEST_F(TestStatisticsFLBA, UnknownSortOrder) {
+  this->fields_.push_back(schema::PrimitiveNode::Make("Column 0", Repetition::REQUIRED,
+                                                Type::FIXED_LEN_BYTE_ARRAY,
+                                                LogicalType::INTERVAL, FLBA_LENGTH));
+  this->SetUpSchema();
+  this->WriteParquet();
+
+  auto pbuffer = parquet_sink_->GetBuffer();
+  // Create a ParquetReader instance
+  std::unique_ptr<parquet::ParquetFileReader> parquet_reader =
+      parquet::ParquetFileReader::Open(
+            std::make_shared<arrow::io::BufferReader>(pbuffer));
+  // Get the File MetaData
+  std::shared_ptr<parquet::FileMetaData> file_metadata = parquet_reader->metadata();
+  std::shared_ptr<parquet::RowGroupMetaData> rg_metadata = file_metadata->RowGroup(0);
+  std::shared_ptr<parquet::ColumnChunkMetaData> cc_metadata =
+        rg_metadata->ColumnChunk(0);
+  // stats should not be set
+  ASSERT_FALSE(cc_metadata->is_stats_set());
+}
+
 }  // namespace test
 }  // namespace parquet