Add stronger inference to unwrapType

urql-graphql · Dec 3, 2019 · 809e7a3 · 809e7a3
1 parent cc633a0
commit 809e7a3
Showing 1 changed file with 7 additions and 4 deletions.
diff --git a/src/ast/node.ts b/src/ast/node.ts
@@ -6,7 +6,7 @@ import {
   InlineFragmentNode,
   FieldNode,
   FragmentDefinitionNode,
-  GraphQLOutputType,
+  GraphQLWrappingType,
   Kind,
   isListType,
   isNonNullType,
@@ -44,9 +44,12 @@ export const isInlineFragment = (
   node: SelectionNode
 ): node is InlineFragmentNode => node.kind === Kind.INLINE_FRAGMENT;
 
-export const unwrapType = (
-  type: null | undefined | GraphQLOutputType
-): GraphQLFlatType | null => {
+export const unwrapType = <
+  T,
+  V = T extends GraphQLWrappingType ? GraphQLFlatType : T
+>(
+  type: null | undefined | T
+): V | null => {
   return type && (isListType(type) || isNonNullType(type))
     ? type.ofType
     : type || null;