Schema warden (#116)

Author: gmac

lib/graphql/stitching/planner.rb

@@ -324,7 +324,7 @@ def expand_interface_selections(current_location, parent_type, input_selections)
         end
 
         if expanded_selections
-          @supergraph.memoized_schema_possible_types(parent_type.graphql_name).each do |possible_type|
+          @request.warden.possible_types(parent_type).each do |possible_type|
             next unless @supergraph.locations_by_type[possible_type.graphql_name].include?(current_location)
 
             type_name = GraphQL::Language::Nodes::TypeName.new(name: possible_type.graphql_name)

lib/graphql/stitching/request.rb

@@ -21,6 +21,9 @@ class Request
       # @return [Hash] contextual object passed through resolver flows.
       attr_reader :context
 
+      # @return [GraphQL::Schema::Warden] a visibility warden for this request.
+      attr_reader :warden
+
       # Creates a new supergraph request.
       # @param supergraph [Supergraph] supergraph instance that resolves the request.
       # @param document [String, GraphQL::Language::Nodes::Document] the request string or parsed AST.
@@ -48,7 +51,11 @@ def initialize(supergraph, document, operation_name: nil, variables: nil, contex
 
         @operation_name = operation_name
         @variables = variables || {}
-        @context = context || GraphQL::Stitching::EMPTY_OBJECT
+
+        @query = GraphQL::Query.new(@supergraph.schema, document: @document, context: context)
+        @warden = @query.warden
+        @context = @query.context
+        @context[:request] = self
       end
 
       # @return [String] the original document string, or a print of the parsed AST document.
@@ -98,14 +105,14 @@ def operation_directives
         end
       end
 
-      # @return [Hash<String, GraphQL::Language::Nodes::AbstractNode>]
+      # @return [Hash<String, GraphQL::Language::Nodes::AbstractNode>] map of variable names to AST type definitions.
       def variable_definitions
         @variable_definitions ||= operation.variables.each_with_object({}) do |v, memo|
           memo[v.name] = v.type
         end
       end
 
-      # @return [Hash<String, GraphQL::Language::Nodes::FragmentDefinition>]
+      # @return [Hash<String, GraphQL::Language::Nodes::FragmentDefinition>] map of fragment names to their AST definitions.
       def fragment_definitions
         @fragment_definitions ||= @document.definitions.each_with_object({}) do |d, memo|
           memo[d.name] = d if d.is_a?(GraphQL::Language::Nodes::FragmentDefinition)
@@ -114,7 +121,8 @@ def fragment_definitions
 
       # Validates the request using the combined supergraph schema.
       def validate
-        @supergraph.schema.validate(@document, context: @context)
+        result = @supergraph.static_validator.validate(@query)
+        result[:errors]
       end
 
       # Prepares the request for stitching by rendering variable defaults and applying @skip/@include conditionals.

lib/graphql/stitching/shaper.rb

@@ -118,7 +118,7 @@ def introspection_field?(parent_type, node)
       def typename_in_type?(typename, type)
         return true if type.graphql_name == typename
 
-        type.kind.abstract? && @supergraph.memoized_schema_possible_types(type.graphql_name).any? do |t|
+        type.kind.abstract? && @request.warden.possible_types(type).any? do |t|
           t.graphql_name == typename
         end
       end

lib/graphql/stitching/supergraph.rb

@@ -72,19 +72,27 @@ def from_definition(schema, executables:)
         end
       end
 
-      attr_reader :schema, :boundaries, :locations_by_type_and_field, :executables
+      # @return [GraphQL::Schema] the composed schema for the supergraph.
+      attr_reader :schema
+
+      # @return [Hash<String, Executable>] a map of executable resources by location.
+      attr_reader :executables
+
+      attr_reader :boundaries, :locations_by_type_and_field
 
       def initialize(schema:, fields: {}, boundaries: {}, executables: {})
         @schema = schema
+        @schema.use(GraphQL::Schema::AlwaysVisible)
+
         @boundaries = boundaries
-        @possible_keys_by_type = {}
-        @possible_keys_by_type_and_location = {}
-        @memoized_schema_possible_types = {}
-        @memoized_schema_fields = {}
-        @memoized_introspection_types = nil
-        @memoized_schema_types = nil
         @fields_by_type_and_location = nil
         @locations_by_type = nil
+        @memoized_introspection_types = nil
+        @memoized_schema_fields = {}
+        @memoized_schema_types = nil
+        @possible_keys_by_type = {}
+        @possible_keys_by_type_and_location = {}
+        @static_validator = nil
 
         # add introspection types into the fields mapping
         @locations_by_type_and_field = memoized_introspection_types.each_with_object(fields) do |(type_name, type), memo|
@@ -156,6 +164,11 @@ def to_definition
         @schema.to_definition
       end
 
+      # @return [GraphQL::StaticValidation::Validator] static validator for the supergraph schema.
+      def static_validator
+        @static_validator ||= @schema.static_validator
+      end
+
       def fields
         @locations_by_type_and_field.reject { |k, _v| memoized_introspection_types[k] }
       end
@@ -172,10 +185,6 @@ def memoized_schema_types
         @memoized_schema_types ||= @schema.types
       end
 
-      def memoized_schema_possible_types(type_name)
-        @memoized_schema_possible_types[type_name] ||= @schema.possible_types(memoized_schema_types[type_name])
-      end
-
       def memoized_schema_fields(type_name)
         @memoized_schema_fields[type_name] ||= begin
           fields = memoized_schema_types[type_name].fields