text: #
  # Copyright (c) 2022, NVIDIA CORPORATION.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  #
  import pytest
  
  from merlin.graph.base_operator import BaseOperator as Operator
  from merlin.graph.graph import Graph
  from merlin.graph.selector import ColumnSelector
  from merlin.schema import Schema
  
  
  @pytest.mark.parametrize("engine", ["parquet"])
  def test_graph_validates_schemas(dataset, engine):
      ops = ["a", "b", "c"] >> Operator()
      graph = Graph(ops)
  
      with pytest.raises(ValueError) as exc_info:
          graph.construct_schema(dataset.schema)
  
      assert "Missing column" in str(exc_info.value)
  
  
  @pytest.mark.parametrize("engine", ["parquet"])
  def test_compute_selector_validates_schemas(dataset, engine):
      op = Operator()
      schema = Schema(["a", "b"])
      selector = ColumnSelector(["c"])
  
      with pytest.raises(ValueError) as exc_info:
          op.compute_selector(schema, selector, ColumnSelector(), ColumnSelector())
  
      assert "Missing column" in str(exc_info.value)
  
  
  @pytest.mark.parametrize("engine", ["parquet"])
  def test_compute_input_schema_validates_schemas(dataset, engine):
      op = Operator()
      schema = Schema(["a", "b"])
      selector = ColumnSelector(["c"])
  
      with pytest.raises(ValueError) as exc_info:
          op.compute_input_schema(schema, Schema(), Schema(), selector)
  
      assert "Missing column" in str(exc_info.value)
  
      with pytest.raises(ValueError) as exc_info:
          op.compute_input_schema(Schema(), schema, Schema(), selector)
  
      assert "Missing column" in str(exc_info.value)
  
      with pytest.raises(ValueError) as exc_info:
          op.compute_input_schema(Schema(), Schema(), schema, selector)
  
      assert "Missing column" in str(exc_info.value)
  
  
  @pytest.mark.parametrize("engine", ["parquet"])
  def test_compute_output_schema_validates_schemas(dataset, engine):
      op = Operator()
      schema = Schema(["a", "b"])
      selector = ColumnSelector(["c"])
  
      with pytest.raises(ValueError) as exc_info:
          op.compute_output_schema(schema, selector)
  
      assert "Missing column" in str(exc_info.value)
  