text: from __future__ import annotations
  
  from pathlib import Path
  from typing import Dict, Text
  
  import pytest
  
  from rasa.engine.storage.resource import Resource
  import rasa.shared.utils.io
  from rasa.engine.exceptions import GraphSchemaException
  from rasa.engine.graph import SchemaNode, GraphSchema
  from tests.engine.graph_components_test_classes import PersistableTestComponent
  
  
  def test_serialize_graph_schema(tmp_path: Path):
      graph_schema = GraphSchema(
          {
              "train": SchemaNode(
                  needs={},
                  uses=PersistableTestComponent,
                  fn="train",
                  constructor_name="create",
                  config={"some_config": 123455, "some more config": [{"nested": "hi"}]},
              ),
              "load": SchemaNode(
                  needs={"resource": "train"},
                  uses=PersistableTestComponent,
                  fn="run_inference",
                  constructor_name="load",
                  config={},
                  is_target=True,
                  resource=Resource("test resource"),
              ),
          },
      )
  
      serialized = graph_schema.as_dict()
  
      # Dump it to make sure it's actually serializable
      file_path = tmp_path / "my_graph.yml"
      rasa.shared.utils.io.write_yaml(serialized, file_path)
  
      serialized_graph_schema_from_file = rasa.shared.utils.io.read_yaml_file(file_path)
      graph_schema_from_file = GraphSchema.from_dict(serialized_graph_schema_from_file)
  
      assert graph_schema_from_file == graph_schema
  
  
  def test_invalid_module_error_when_deserializing_schemas(tmp_path: Path):
      graph_schema = GraphSchema(
          {
              "train": SchemaNode(
                  needs={},
                  uses=PersistableTestComponent,
                  fn="train",
                  constructor_name="create",
                  config={"some_config": 123455, "some more config": [{"nested": "hi"}]},
              ),
          }
      )
  
      serialized = graph_schema.as_dict()
  
      # Pretend module is for some reason invalid
      serialized["nodes"]["train"]["uses"] = "invalid.class"
  
      # Dump it to make sure it's actually serializable
      file_path = tmp_path / "my_graph.yml"
      rasa.shared.utils.io.write_yaml(serialized, file_path)
  
      serialized_graph_schema_from_file = rasa.shared.utils.io.read_yaml_file(file_path)
  
      with pytest.raises(GraphSchemaException):
          _ = GraphSchema.from_dict(serialized_graph_schema_from_file)
  
  
  def test_minimal_graph_schema():
      def test_schema_node(needs: Dict[Text, Text], target: bool = False) -> SchemaNode:
          return SchemaNode(
              needs=needs,
              uses=None,
              fn="",
              constructor_name="",
              config={},
              is_target=target,
          )
  
      test_schema = GraphSchema(
          {
              "1": test_schema_node({"i": "3"}, True),
              "2": test_schema_node({"i": "3"}),
              "3": test_schema_node({"i": "4"}),
              "4": test_schema_node({}),
              "5": test_schema_node({"i": "6"}),
              "6": test_schema_node({}),
              "7": test_schema_node({}),
              "8": test_schema_node({"i": "9"}, True),
              "9": test_schema_node({"i": "__input__"}),
          }
      )
      assert test_schema.minimal_graph_schema() == GraphSchema(
          {
              "1": test_schema_node({"i": "3"}, True),
              "3": test_schema_node({"i": "4"}),
              "4": test_schema_node({}),
              "8": test_schema_node({"i": "9"}, True),
              "9": test_schema_node({"i": "__input__"}),
          }
      )
  
      assert test_schema.minimal_graph_schema(targets=["8"]) == GraphSchema(
          {
              "8": test_schema_node({"i": "9"}, True),
              "9": test_schema_node({"i": "__input__"}),
          }
      )
  