Be stricter about types

Author: JoviDeCroock

src/language/ast.ts

@@ -530,6 +530,11 @@ export interface SemanticNonNullTypeNode {
 /** Type Reference */
 
 export type TypeNode = NamedTypeNode | ListTypeNode | NonNullTypeNode;
+export type SchemaOutputTypeNode =
+  | NamedTypeNode
+  | ListTypeNode
+  | NonNullTypeNode
+  | SemanticNonNullTypeNode;
 
 export interface NamedTypeNode {
   readonly kind: Kind.NAMED_TYPE;
@@ -540,7 +545,13 @@ export interface NamedTypeNode {
 export interface ListTypeNode {
   readonly kind: Kind.LIST_TYPE;
   readonly loc?: Location;
-  readonly type: TypeNode | SemanticNonNullTypeNode;
+  readonly type: TypeNode;
+}
+
+export interface SchemaListTypeNode {
+  readonly kind: Kind.LIST_TYPE;
+  readonly loc?: Location;
+  readonly type: SchemaOutputTypeNode;
 }
 
 export interface NonNullTypeNode {
@@ -605,7 +616,7 @@ export interface FieldDefinitionNode {
   readonly description?: StringValueNode;
   readonly name: NameNode;
   readonly arguments?: ReadonlyArray<InputValueDefinitionNode>;
-  readonly type: TypeNode | SemanticNonNullTypeNode;
+  readonly type: SchemaOutputTypeNode;
   readonly directives?: ReadonlyArray<ConstDirectiveNode>;
 }
 

src/utilities/extendSchema.ts

@@ -24,9 +24,8 @@ import type {
   ScalarTypeExtensionNode,
   SchemaDefinitionNode,
   SchemaExtensionNode,
-  SemanticNonNullTypeNode,
+  SchemaOutputTypeNode,
   TypeDefinitionNode,
-  TypeNode,
   UnionTypeDefinitionNode,
   UnionTypeExtensionNode,
 } from '../language/ast';
@@ -432,9 +431,7 @@ export function extendSchemaImpl(
     return type;
   }
 
-  function getWrappedType(
-    node: TypeNode | SemanticNonNullTypeNode,
-  ): GraphQLType {
+  function getWrappedType(node: SchemaOutputTypeNode): GraphQLType {
     if (node.kind === Kind.LIST_TYPE) {
       return new GraphQLList(getWrappedType(node.type));
     }

src/utilities/typeFromAST.ts

@@ -39,7 +39,7 @@ export function typeFromAST(
 ): GraphQLType | undefined {
   switch (typeNode.kind) {
     case Kind.LIST_TYPE: {
-      const innerType = typeFromAST(schema, typeNode.type as TypeNode);
+      const innerType = typeFromAST(schema, typeNode.type);
       return innerType && new GraphQLList(innerType);
     }
     case Kind.NON_NULL_TYPE: {