feat: allow embedding the operation result type

Author: n1ru4l

packages/core/src/index.ts

@@ -1,12 +1,14 @@
 import { DocumentNode } from 'graphql';
 
-export interface TypedDocumentNode<Result = { [key: string]: any }, Variables = { [key: string]: any }> extends DocumentNode {
+export type OperationResultType = "stream" | "single";
+
+export interface TypedDocumentNode<Result = { [key: string]: any }, Variables = { [key: string]: any }, ResultType extends OperationResultType = any> extends DocumentNode {
   /**
    * This type is used to ensure that the variables you pass in to the query are assignable to Variables
    * and that the Result is assignable to whatever you pass your result to. The method is never actually
    * implemented, but the type is valid because we list it as optional
    */
-  __apiType?: (variables: Variables) => Result;
+  __apiType?: (variables: Variables, resultType: ResultType) => Result;
 }
 
 /**
@@ -15,12 +17,20 @@ export interface TypedDocumentNode<Result = { [key: string]: any }, Variables =
  * const myQuery = { ... }; // TypedDocumentNode<R, V> 
  * type ResultType = ResultOf<typeof myQuery>; // Now it's R
  */
-export type ResultOf<T> = T extends TypedDocumentNode<infer ResultType, infer VariablesType> ? ResultType : never;
+export type ResultOf<T> = T extends TypedDocumentNode<infer ResultType, any> ? ResultType : never;
 
 /**
  * Helper for extracting a TypeScript type for operation variables from a TypedDocumentNode.
  * @example
  * const myQuery = { ... }; // TypedDocumentNode<R, V> 
  * type VariablesType = VariablesOf<typeof myQuery>; // Now it's V
  */
-export type VariablesOf<T> = T extends TypedDocumentNode<infer ResultType, infer VariablesType> ? VariablesType : never;
+export type VariablesOf<T> = T extends TypedDocumentNode<any, infer VariablesType> ? VariablesType : never;
+
+/**
+ * Helper for extracting a TypeScript type for operation type from a TypedDocumentNode.
+ * @example
+ * const myQuery = { ... }; // TypedDocumentNode<R, V, O> 
+ * type OperationType = VariablesOf<typeof myQuery>; // Now it's O
+ */
+export type OperationTypeOf<T> = T extends TypedDocumentNode<any, any, infer OperationType> ? OperationType : never;