From c55ac609582a1e2eabfad737e3704aa7fc231db3 Mon Sep 17 00:00:00 2001
From: Ivan Goncharov <ivan.goncharov.ua@gmail.com>
Date: Mon, 6 Dec 2021 19:00:25 +0200
Subject: [PATCH] Refine getNamedType() for Input and Output types (#3410)

Backport of #3063

This introduces type definitions `GraphQLNamedInputType` and `GraphQLNamedOutputType` as the subsets of `GraphQLNamedType`, and adds function overrides for `getNamedType()` such that if an input or output type is provided, one of these refined subset types is returned.

Co-authored-by: Lee Byron <lee@leebyron.com>
---
 src/index.d.ts           |  2 ++
 src/index.js             |  2 ++
 src/type/definition.d.ts | 14 +++++++++++---
 src/type/definition.js   | 14 +++++++++++---
 src/type/index.d.ts      |  2 ++
 src/type/index.js        |  2 ++
 6 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/src/index.d.ts b/src/index.d.ts
index 13a465b4e1..e0707adeaa 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -138,6 +138,8 @@ export {
   GraphQLNullableType,
   GraphQLNamedType,
   Thunk,
+  GraphQLNamedInputType,
+  GraphQLNamedOutputType,
   GraphQLSchemaConfig,
   GraphQLSchemaExtensions,
   GraphQLDirectiveConfig,
diff --git a/src/index.js b/src/index.js
index 104ab88658..4387ce14fa 100644
--- a/src/index.js
+++ b/src/index.js
@@ -137,6 +137,8 @@ export type {
   GraphQLNullableType,
   GraphQLNamedType,
   Thunk,
+  GraphQLNamedInputType,
+  GraphQLNamedOutputType,
   GraphQLSchemaConfig,
   GraphQLDirectiveConfig,
   GraphQLArgument,
diff --git a/src/type/definition.d.ts b/src/type/definition.d.ts
index 06799981f9..b304d226cf 100644
--- a/src/type/definition.d.ts
+++ b/src/type/definition.d.ts
@@ -254,19 +254,27 @@ export function getNullableType<T extends GraphQLNullableType>(
 /**
  * These named types do not include modifiers like List or NonNull.
  */
-export type GraphQLNamedType =
+export type GraphQLNamedType = GraphQLNamedInputType | GraphQLNamedOutputType;
+
+export type GraphQLNamedInputType =
+  | GraphQLScalarType
+  | GraphQLEnumType
+  | GraphQLInputObjectType;
+
+export type GraphQLNamedOutputType =
   | GraphQLScalarType
   | GraphQLObjectType
   | GraphQLInterfaceType
   | GraphQLUnionType
-  | GraphQLEnumType
-  | GraphQLInputObjectType;
+  | GraphQLEnumType;
 
 export function isNamedType(type: any): type is GraphQLNamedType;
 
 export function assertNamedType(type: any): GraphQLNamedType;
 
 export function getNamedType(type: undefined): undefined;
+export function getNamedType(type: GraphQLInputType): GraphQLNamedInputType;
+export function getNamedType(type: GraphQLOutputType): GraphQLNamedOutputType;
 export function getNamedType(type: GraphQLType): GraphQLNamedType;
 
 /**
diff --git a/src/type/definition.js b/src/type/definition.js
index 2b762fb79d..9b944d3fd1 100644
--- a/src/type/definition.js
+++ b/src/type/definition.js
@@ -493,13 +493,19 @@ export function getNullableType(type) {
 /**
  * These named types do not include modifiers like List or NonNull.
  */
-export type GraphQLNamedType =
+export type GraphQLNamedType = GraphQLNamedInputType | GraphQLNamedOutputType;
+
+export type GraphQLNamedInputType =
+  | GraphQLScalarType
+  | GraphQLEnumType
+  | GraphQLInputObjectType;
+
+export type GraphQLNamedOutputType =
   | GraphQLScalarType
   | GraphQLObjectType
   | GraphQLInterfaceType
   | GraphQLUnionType
-  | GraphQLEnumType
-  | GraphQLInputObjectType;
+  | GraphQLEnumType;
 
 export function isNamedType(type: mixed): boolean %checks {
   return (
@@ -521,6 +527,8 @@ export function assertNamedType(type: mixed): GraphQLNamedType {
 
 /* eslint-disable no-redeclare */
 declare function getNamedType(type: void | null): void;
+declare function getNamedType(type: GraphQLInputType): GraphQLNamedInputType;
+declare function getNamedType(type: GraphQLOutputType): GraphQLNamedOutputType;
 declare function getNamedType(type: GraphQLType): GraphQLNamedType;
 export function getNamedType(type) {
   /* eslint-enable no-redeclare */
diff --git a/src/type/index.d.ts b/src/type/index.d.ts
index 9686f413b7..363531985e 100644
--- a/src/type/index.d.ts
+++ b/src/type/index.d.ts
@@ -74,6 +74,8 @@ export {
   GraphQLNullableType,
   GraphQLNamedType,
   Thunk,
+  GraphQLNamedInputType,
+  GraphQLNamedOutputType,
   GraphQLArgument,
   GraphQLArgumentConfig,
   GraphQLArgumentExtensions,
diff --git a/src/type/index.js b/src/type/index.js
index 811d50247a..8aa50d678b 100644
--- a/src/type/index.js
+++ b/src/type/index.js
@@ -129,6 +129,8 @@ export type {
   GraphQLNullableType,
   GraphQLNamedType,
   Thunk,
+  GraphQLNamedInputType,
+  GraphQLNamedOutputType,
   GraphQLArgument,
   GraphQLArgumentConfig,
   GraphQLEnumTypeConfig,