c_glib/test/parquet/test-statistics.rb

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class TestParquetStatistics < Test::Unit::TestCase
  include Helper::Buildable

  def setup
    omit("Parquet is required") unless defined?(::Parquet)
    @file = Tempfile.open(["data", ".parquet"])
    @table = build_table("int32" => build_int32_array([nil, 2, 2, 9]))
    writer = Parquet::ArrowFileWriter.new(@table.schema, @file.path)
    chunk_size = 1024
    writer.write_table(@table, chunk_size)
    writer.close
    reader = Parquet::ArrowFileReader.new(@file.path)
    @statistics = reader.metadata.get_row_group(0).get_column_chunk(0).statistics
  end

  test("#==") do
    omit("parquet::Statistics::Equals() is broken.")
    reader = Parquet::ArrowFileReader.new(@file.path)
    other_statistics =
      reader.metadata.get_row_group(0).get_column_chunk(0).statistics
    assert do
      @statistics == other_statistics
    end
  end

  test("#has_n_nulls?") do
    assert do
      @statistics.has_n_nulls?
    end
  end

  test("#n_nulls") do
    assert_equal(1, @statistics.n_nulls)
  end

  test("#has_n_distinct_values?") do
    assert do
      @statistics.has_n_distinct_values?
    end
  end

  test("#n_distinct_values") do
    # It seems that writer doesn't support this.
    assert_equal(0, @statistics.n_distinct_values)
  end

  test("#n_values") do
    assert_equal(3, @statistics.n_values)
  end

  test("#has_min_max?") do
    assert do
      @statistics.has_min_max?
    end
  end
end