add a validation code to fix issue I1YKU6 and corresponded ut, fix format issue I1YKXL

mindspore/ccsrc/minddata/dataset/engine/datasetops/source/tf_reader_op.cc

@@ -642,7 +642,7 @@ Status TFReaderOp::LoadExample(const dataengine::Example *tf_file, std::unique_p
     const google::protobuf::Map<std::string, dataengine::Feature> &feature_map = example_features.feature();
     auto iter_column = feature_map.find(current_col.name());
     if (iter_column == feature_map.end()) {
-      RETURN_STATUS_UNEXPECTED("Invalid parameter, column name: " + current_col.name() + "does not exist.");
+      RETURN_STATUS_UNEXPECTED("Invalid parameter, column name: " + current_col.name() + " does not exist.");
     }
     const dataengine::Feature &column_values_list = iter_column->second;
     RETURN_IF_NOT_OK(LoadFeature(tensor_table, column_values_list, current_col, row, col));

mindspore/ccsrc/minddata/dataset/include/datasets.h

@@ -482,6 +482,14 @@ std::shared_ptr<TFRecordNode> TFRecord(const std::vector<std::string> &dataset_f
     MS_LOG(ERROR) << "TFRecordNode: Invalid input, shard_id: " << shard_id << ", num_shards: " << num_shards;
     return nullptr;
   }
+
+  if (cache == nullptr && !shard_equal_rows && dataset_files.size() < num_shards) {
+    // This check only makes sense in a non-cache path. We should make sure there is at least one file per
+    // shard in file-based sharding
+    MS_LOG(ERROR) << "TFRecordNode: Invalid number of dataset files, should at least be " << std::to_string(num_shards);
+    return nullptr;
+  }
+
   std::shared_ptr<TFRecordNode> ds = nullptr;
   if constexpr (std::is_same<T, std::nullptr_t>::value || std::is_same<T, std::shared_ptr<SchemaObj>>::value) {
     std::shared_ptr<SchemaObj> schema_obj = schema;

tests/ut/cpp/dataset/c_api_dataset_tfrecord_test.cc

@@ -368,12 +368,14 @@ TEST_F(MindDataTestPipeline, TestTFRecordDatasetShard) {
 
   // Create a TFRecord Dataset
   // Each file has two columns("image", "label") and 3 rows
-  std::vector<std::string> files = {datasets_root_path_ + "/test_tf_file_3_images2/train-0000-of-0001.data",
-                                    datasets_root_path_ + "/test_tf_file_3_images2/train-0000-of-0002.data",
-                                    datasets_root_path_ + "/test_tf_file_3_images2/train-0000-of-0003.data"};
-  std::shared_ptr<Dataset> ds1 = TFRecord({files}, "", {}, 0, ShuffleMode::kFalse, 2, 1, true);
+  std::vector<std::string> files = {
+    datasets_root_path_ + "/test_tf_file_3_images2/train-0000-of-0001.data",
+    datasets_root_path_ + "/test_tf_file_3_images2/train-0000-of-0002.data",
+    datasets_root_path_ + "/test_tf_file_3_images2/train-0000-of-0003.data"
+  };
+  std::shared_ptr<Dataset> ds1 = TFRecord(files, "", {}, 0, ShuffleMode::kFalse, 2, 1, true);
   EXPECT_NE(ds1, nullptr);
-  std::shared_ptr<Dataset> ds2 = TFRecord({files}, "", {}, 0, ShuffleMode::kFalse, 2, 1, false);
+  std::shared_ptr<Dataset> ds2 = TFRecord(files, "", {}, 0, ShuffleMode::kFalse, 2, 1, false);
   EXPECT_NE(ds2, nullptr);
 
   // Create an iterator over the result of the above dataset
@@ -435,6 +437,12 @@ TEST_F(MindDataTestPipeline, TestTFRecordDatasetExeception) {
   // This case expected to fail because shard_id is out_of_bound.
   std::shared_ptr<Dataset> ds7 = TFRecord({file_path}, "", {}, 10, ShuffleMode::kFalse, 3, 3);
   EXPECT_EQ(ds7, nullptr);
+
+  // This case expected to fail because the provided number of files < num_shards in file-based sharding.
+  std::string file_path1 = datasets_root_path_ + "/test_tf_file_3_images2/train-0000-of-0001.data";
+  std::string file_path2 = datasets_root_path_ + "/test_tf_file_3_images2/train-0000-of-0002.data";
+  std::shared_ptr<Dataset> ds8 = TFRecord({file_path1, file_path2}, "", {}, 0, ShuffleMode::kFalse, 3);
+  EXPECT_EQ(ds8, nullptr);
 }
 
 TEST_F(MindDataTestPipeline, TestTFRecordDatasetExeception2) {