Unify rest of error messages

Replicates graphql/graphql-js@10b8e95

Author: Cito

docs/usage/validator.rst

@@ -24,7 +24,7 @@ As a result, you will get a complete list of all errors that the validators has
 In this case, we will get::
 
     [GraphQLError(
-        'Expected type String!, found NEWHOPE.',
+        "Expected value of type 'String!', found NEWHOPE.",
         locations=[SourceLocation(line=3, column=17)]),
      GraphQLError(
         "Cannot query field 'homeTown' on type 'Human'."

src/graphql/validation/rules/executable_definitions.py

@@ -29,9 +29,12 @@ def enter_document(self, node: DocumentNode, *_args):
                     if isinstance(
                         definition, (SchemaDefinitionNode, SchemaExtensionNode)
                     )
-                    else cast(
-                        Union[DirectiveDefinitionNode, TypeDefinitionNode], definition,
-                    ).name.value
+                    else "'{}'".format(
+                        cast(
+                            Union[DirectiveDefinitionNode, TypeDefinitionNode],
+                            definition,
+                        ).name.value
+                    )
                 )
                 self.report_error(
                     GraphQLError(

src/graphql/validation/rules/known_argument_names.py

@@ -77,8 +77,8 @@ def enter_argument(self, arg_node: ArgumentNode, *args):
             suggestions = suggestion_list(arg_name, known_args_names)
             context.report_error(
                 GraphQLError(
-                    f"Unknown argument '{arg_name}' on field '{field_name}'"
-                    f" of type '{parent_type.name}'."
+                    f"Unknown argument '{arg_name}'"
+                    f" on field '{parent_type.name}.{field_name}'."
                     + did_you_mean([f"'{s}'" for s in suggestions]),
                     arg_node,
                 )

src/graphql/validation/rules/known_directives.py

@@ -49,13 +49,13 @@ def enter_directive(self, node: DirectiveNode, _key, _parent, _path, ancestors):
             if candidate_location and candidate_location not in locations:
                 self.report_error(
                     GraphQLError(
-                        f"Directive '{name}'"
+                        f"Directive '@{name}'"
                         f" may not be used on {candidate_location.value}.",
                         node,
                     )
                 )
         else:
-            self.report_error(GraphQLError(f"Unknown directive '{name}'.", node))
+            self.report_error(GraphQLError(f"Unknown directive '@{name}'.", node))
 
 
 _operation_location = {

src/graphql/validation/rules/no_fragment_cycles.py

@@ -58,11 +58,11 @@ def detect_cycle_recursive(self, fragment: FragmentDefinitionNode):
                     self.detect_cycle_recursive(spread_fragment)
             else:
                 cycle_path = spread_path[cycle_index:]
-                via_names = [s.name.value for s in cycle_path[:-1]]
+                via_path = ", ".join("'" + s.name.value + "'" for s in cycle_path[:-1])
                 self.report_error(
                     GraphQLError(
                         f"Cannot spread fragment '{spread_name}' within itself"
-                        + (f" via {', '.join(via_names)}." if via_names else "."),
+                        + (f" via {via_path}." if via_path else "."),
                         cycle_path,
                     )
                 )

src/graphql/validation/rules/overlapping_fields_can_be_merged.py

@@ -545,7 +545,7 @@ def find_conflict(
         name2 = node2.name.value
         if name1 != name2:
             return (
-                (response_name, f"{name1} and {name2} are different fields"),
+                (response_name, f"'{name1}' and '{name2}' are different fields"),
                 [node1],
                 [node2],
             )
@@ -556,7 +556,7 @@ def find_conflict(
 
     if type1 and type2 and do_types_conflict(type1, type2):
         return (
-            (response_name, f"they return conflicting types {type1} and {type2}"),
+            (response_name, f"they return conflicting types '{type1}' and '{type2}'"),
             [node1],
             [node2],
         )

src/graphql/validation/rules/possible_type_extensions.py

@@ -49,7 +49,7 @@ def check_extension(self, node: TypeExtensionNode, *_args):
 
         if expected_kind:
             if expected_kind != node.kind:
-                kind_str = extension_kind_to_type_name(expected_kind)
+                kind_str = extension_kind_to_type_name(node.kind)
                 self.report_error(
                     GraphQLError(
                         f"Cannot extend non-{kind_str} type '{type_name}'.",

src/graphql/validation/rules/unique_directive_names.py

@@ -24,7 +24,7 @@ def enter_directive_definition(self, node: DirectiveDefinitionNode, *_args):
         if self.schema and self.schema.get_directive(directive_name):
             self.report_error(
                 GraphQLError(
-                    f"Directive '{directive_name}' already exists in the schema."
+                    f"Directive '@{directive_name}' already exists in the schema."
                     " It cannot be redefined.",
                     node.name,
                 )
@@ -33,7 +33,7 @@ def enter_directive_definition(self, node: DirectiveDefinitionNode, *_args):
             if directive_name in self.known_directive_names:
                 self.report_error(
                     GraphQLError(
-                        f"There can be only one directive named '{directive_name}'.",
+                        f"There can be only one directive named '@{directive_name}'.",
                         [self.known_directive_names[directive_name], node.name],
                     )
                 )

src/graphql/validation/rules/unique_directives_per_location.py

@@ -46,7 +46,7 @@ def enter(self, node: Node, *_args):
                     if directive_name in known_directives:
                         self.report_error(
                             GraphQLError(
-                                f"The directive '{directive_name}'"
+                                f"The directive '@{directive_name}'"
                                 " can only be used once at this location.",
                                 [known_directives[directive_name], directive],
                             )

src/graphql/validation/rules/unique_variable_names.py

@@ -26,7 +26,7 @@ def enter_variable_definition(self, node: VariableDefinitionNode, *_args):
         if variable_name in known_variable_names:
             self.report_error(
                 GraphQLError(
-                    f"There can be only one variable named '{variable_name}'.",
+                    f"There can be only one variable named '${variable_name}'.",
                     [known_variable_names[variable_name], node.variable.name],
                 )
             )