Revert "Remove deprecated type_info argument of validate() function"

This reverts commit 2d90cc1.

Replicates graphql/graphql-js@75635f0

src/graphql/validation/validate.py

@@ -2,7 +2,7 @@
 
 from ..error import GraphQLError
 from ..language import DocumentNode, ParallelVisitor, visit
-from ..pyutils import is_collection
+from ..pyutils import inspect, is_collection
 from ..type import GraphQLSchema, assert_valid_schema
 from ..utilities import TypeInfo, TypeInfoVisitor
 from .rules import ASTValidationRule
@@ -22,6 +22,7 @@ def validate(
     document_ast: DocumentNode,
     rules: Optional[Collection[Type[ASTValidationRule]]] = None,
     max_errors: Optional[int] = None,
+    type_info: Optional[TypeInfo] = None,
 ) -> List[GraphQLError]:
     """Implements the "Validation" section of the spec.
 
@@ -38,6 +39,8 @@ def validate(
     Validate will stop validation after a ``max_errors`` limit has been reached.
     Attackers can send pathologically invalid queries to induce a DoS attack,
     so by default ``max_errors`` set to 100 errors.
+
+    Providing a custom TypeInfo instance is deprecated and will be removed in v3.3.
     """
     if not document_ast or not isinstance(document_ast, DocumentNode):
         raise TypeError("Must provide document.")
@@ -47,6 +50,10 @@ def validate(
         max_errors = 100
     elif not isinstance(max_errors, int):
         raise TypeError("The maximum number of errors must be passed as an int.")
+    if type_info is None:
+        type_info = TypeInfo(schema)
+    elif not isinstance(type_info, TypeInfo):
+        raise TypeError(f"Not a TypeInfo object: {inspect(type_info)}.")
     if rules is None:
         rules = specified_rules
     elif not is_collection(rules) or not all(
@@ -69,7 +76,6 @@ def on_error(error: GraphQLError) -> None:
             raise ValidationAbortedError
         errors.append(error)
 
-    type_info = TypeInfo(schema)
     context = ValidationContext(schema, document_ast, type_info, on_error)
 
     # This uses a specialized visitor which runs multiple visitors in parallel,

tests/validation/test_validation.py

@@ -2,7 +2,7 @@
 
 from graphql.error import GraphQLError
 from graphql.language import parse
-from graphql.utilities import build_schema
+from graphql.utilities import TypeInfo, build_schema
 from graphql.validation import ValidationRule, validate
 
 from .harness import test_schema
@@ -15,6 +15,14 @@ def rejects_invalid_documents():
             assert validate(test_schema, None)  # type: ignore
         assert str(exc_info.value) == "Must provide document."
 
+    def rejects_invalid_type_info():
+        with raises(TypeError) as exc_info:
+            # noinspection PyTypeChecker
+            assert validate(
+                test_schema, parse("query { name }"), type_info={}  # type: ignore
+            )
+        assert str(exc_info.value) == "Not a TypeInfo object: {}."
+
     def rejects_invalid_rules():
         with raises(TypeError) as exc_info:
             # noinspection PyTypeChecker
@@ -72,6 +80,37 @@ def detects_unknown_fields():
             {"message": "Cannot query field 'unknown' on type 'QueryRoot'."}
         ]
 
+    def deprecated_validates_using_a_custom_type_info():
+        # This TypeInfo will never return a valid field.
+        type_info = TypeInfo(test_schema, None, lambda *args: None)
+
+        doc = parse(
+            """
+            query {
+              human {
+                pets {
+                  ... on Cat {
+                    meowsVolume
+                  }
+                  ... on Dog {
+                    barkVolume
+                  }
+                }
+              }
+            }
+            """
+        )
+
+        errors = validate(test_schema, doc, None, None, type_info)
+
+        assert [error.message for error in errors] == [
+            "Cannot query field 'human' on type 'QueryRoot'. Did you mean 'human'?",
+            "Cannot query field 'meowsVolume' on type 'Cat'."
+            " Did you mean 'meowsVolume'?",
+            "Cannot query field 'barkVolume' on type 'Dog'."
+            " Did you mean 'barkVolume'?",
+        ]
+
     def validates_using_a_custom_rule():
         schema = build_schema(
             """