Function TEST

cpp/src/arrow/array/array_struct_test.cc:80–142

}

TEST(StructArray, FromFieldNames) {
  std::shared_ptr<Array> a, b, c, array, expected;
  a = ArrayFromJSON(int32(), "[4, null]");
  b = ArrayFromJSON(utf8(), R"([null, "foo"])");
  std::vector<std::string> field_names = {"a", "b"};

  auto res = StructArray::Make({a, b}, field_names);
  ASSERT_OK(res);
  array = *res;
  expected = ArrayFromJSON(struct_({field("a", int32()), field("b", utf8())}),
                           R"([{"a": 4, "b": null}, {"a": null, "b": "foo"}])");
  AssertArraysEqual(*array, *expected);

  // With non-zero offsets
  res =
      StructArray::Make({a, b}, field_names, /*null_bitmap =*/nullptr, /*null_count =*/0,
                        /*offset =*/1);
  ASSERT_OK(res);
  array = *res;
  expected = ArrayFromJSON(struct_({field("a", int32()), field("b", utf8())}),
                           R"([{"a": null, "b": "foo"}])");
  AssertArraysEqual(*array, *expected);

  res =
      StructArray::Make({a, b}, field_names, /*null_bitmap =*/nullptr, /*null_count =*/0,
                        /*offset =*/2);
  ASSERT_OK(res);
  array = *res;
  expected = ArrayFromJSON(struct_({field("a", int32()), field("b", utf8())}), R"([])");
  AssertArraysEqual(*array, *expected);

  // Offset greater than length
  res =
      StructArray::Make({a, b}, field_names, /*null_bitmap =*/nullptr, /*null_count =*/0,
                        /*offset =*/3);
  ASSERT_RAISES(IndexError, res);

  // With null bitmap
  std::shared_ptr<Buffer> null_bitmap;
  BitmapFromVector<bool>({false, true}, &null_bitmap);
  res = StructArray::Make({a, b}, field_names, null_bitmap);
  ASSERT_OK(res);
  array = *res;
  expected = ArrayFromJSON(struct_({field("a", int32()), field("b", utf8())}),
                           R"([null, {"a": null, "b": "foo"}])");
  AssertArraysEqual(*array, *expected);

  // Mismatching array lengths
  field_names = {"a", "c"};
  c = ArrayFromJSON(int64(), "[1, 2, 3]");
  res = StructArray::Make({a, c}, field_names);
  ASSERT_RAISES(Invalid, res);

  // Mismatching number of fields
  field_names = {"a", "b", "c"};
  res = StructArray::Make({a, b}, field_names);
  ASSERT_RAISES(Invalid, res);