Function TEST

cpp/src/arrow/dataset/discovery_test.cc:421–451

}

TEST(UnionDatasetFactoryTest, Basic) {
  auto f64 = field("f64", float64());
  auto i32 = field("i32", int32());
  auto i32_req = field("i32", int32(), /*nullable*/ false);
  auto str = field("str", utf8());

  auto schema_1 = schema({f64, i32_req});
  auto schema_2 = schema({f64, i32});
  auto schema_3 = schema({str, i32});

  auto dataset_1 = DatasetFactoryFromSchemas({schema_1, schema_2});
  auto dataset_2 = DatasetFactoryFromSchemas({schema_2});
  auto dataset_3 = DatasetFactoryFromSchemas({schema_3});

  ASSERT_OK_AND_ASSIGN(auto factory,
                       UnionDatasetFactory::Make({dataset_1, dataset_2, dataset_3}));

  ASSERT_OK_AND_ASSIGN(auto schemas, factory->InspectSchemas({}));
  AssertSchemasAre(schemas, {schema_2, schema_2, schema_3});

  auto expected_schema = schema({f64, i32, str});
  ASSERT_OK_AND_ASSIGN(auto inspected, factory->Inspect());
  EXPECT_EQ(*inspected, *expected_schema);

  ASSERT_OK_AND_ASSIGN(auto dataset, factory->Finish());
  EXPECT_EQ(*dataset->schema(), *expected_schema);

  auto f64_schema = schema({f64});
  ASSERT_OK_AND_ASSIGN(dataset, factory->Finish(f64_schema));
  EXPECT_EQ(*dataset->schema(), *f64_schema);
}

TEST(UnionDatasetFactoryTest, ConflictingSchemas) {
  auto f64 = field("f64", float64());