typescript@4.7 readiness (refine generic typings via extends) (#4382

)

* Install typescript@4.7.0-beta and fix one of the TS errors

* Resolve remaining TS errors

* Fix ambiguous typings

* Revert TS version back to latest

* Add changeset

.changeset/slow-singers-pull.md

@@ -0,0 +1,21 @@
+---
+'@graphql-tools/delegate': patch
+'@graphql-tools/links': patch
+'@graphql-tools/git-loader': patch
+'@graphql-tools/url-loader': patch
+'@graphql-tools/stitch': patch
+'@graphql-tools/utils': patch
+'@graphql-tools/wrap': patch
+---
+
+Refine generic typings using `extends X` when appropriate
+
+Typescript 4.7 has stricter requirements around generics
+which is explained well in the related PR:
+https://github.com/microsoft/TypeScript/pull/48366
+
+These changes resolve the errors that these packages will
+face when attempting to upgrade to TS 4.7 (still in beta
+at the time of writing this). Landing these changes now
+will allow other TS libraries which depend on these
+packages to experiment with TS 4.7 in the meantime.

packages/delegate/src/Transformer.ts

@@ -11,7 +11,7 @@ interface Transformation<TContext> {
   context: Record<string, any>;
 }
 
-export class Transformer<TContext = Record<string, any>> {
+export class Transformer<TContext extends Record<string, any> = Record<string, any>> {
   private transformations: Array<Transformation<TContext>> = [];
   private delegationContext: DelegationContext<TContext>;
 
@@ -51,7 +51,7 @@ export class Transformer<TContext = Record<string, any>> {
   public transformResult(originalResult: ExecutionResult) {
     let result = originalResult;
 
-    // from rigth to left
+    // from right to left
     for (let i = this.transformations.length - 1; i >= 0; i--) {
       const transformation = this.transformations[i];
       if (transformation.transform.transformResult) {

packages/delegate/src/checkResultAndHandleErrors.ts

@@ -5,7 +5,7 @@ import { AggregateError, getResponseKeyFromInfo, ExecutionResult, relocatedError
 import { DelegationContext } from './types';
 import { resolveExternalValue } from './resolveExternalValue';
 
-export function checkResultAndHandleErrors<TContext>(
+export function checkResultAndHandleErrors<TContext extends Record<string, any>>(
   result: ExecutionResult,
   delegationContext: DelegationContext<TContext>
 ): any {

packages/delegate/src/delegateToSchema.ts

@@ -38,9 +38,10 @@ import { Subschema } from './Subschema';
 import { createRequest, getDelegatingOperation } from './createRequest';
 import { Transformer } from './Transformer';
 
-export function delegateToSchema<TContext = Record<string, any>, TArgs = any>(
-  options: IDelegateToSchemaOptions<TContext, TArgs>
-): any {
+export function delegateToSchema<
+  TContext extends Record<string, any> = Record<string, any>,
+  TArgs extends Record<string, any> = any
+>(options: IDelegateToSchemaOptions<TContext, TArgs>): any {
   const {
     info,
     schema,
@@ -85,9 +86,10 @@ function getDelegationReturnType(
   return rootType.getFields()[fieldName].type;
 }
 
-export function delegateRequest<TContext = Record<string, any>, TArgs = any>(
-  options: IDelegateRequestOptions<TContext, TArgs>
-) {
+export function delegateRequest<
+  TContext extends Record<string, any> = Record<string, any>,
+  TArgs extends Record<string, any> = any
+>(options: IDelegateRequestOptions<TContext, TArgs>) {
   const delegationContext = getDelegationContext(options);
 
   const transformer = new Transformer<TContext>(delegationContext);
@@ -112,7 +114,7 @@ export function delegateRequest<TContext = Record<string, any>, TArgs = any>(
     .resolve();
 }
 
-function getDelegationContext<TContext>({
+function getDelegationContext<TContext extends Record<string, any>>({
   request,
   schema,
   fieldName,
@@ -193,7 +195,9 @@ function validateRequest(delegationContext: DelegationContext<any>, document: Do
 
 const GLOBAL_CONTEXT = {};
 
-function getExecutor<TContext>(delegationContext: DelegationContext<TContext>): Executor<TContext> {
+function getExecutor<TContext extends Record<string, any>>(
+  delegationContext: DelegationContext<TContext>
+): Executor<TContext> {
   const { subschemaConfig, targetSchema, context } = delegationContext;
 
   let executor: Executor = subschemaConfig?.executor || createDefaultExecutor(targetSchema);

packages/delegate/src/resolveExternalValue.ts

@@ -19,7 +19,7 @@ import { StitchingInfo, SubschemaConfig } from './types';
 import { annotateExternalObject, isExternalObject, mergeFields } from './mergeFields';
 import { Subschema } from './Subschema';
 
-export function resolveExternalValue<TContext>(
+export function resolveExternalValue<TContext extends Record<string, any>>(
   result: any,
   unpathedErrors: Array<GraphQLError>,
   subschema: GraphQLSchema | SubschemaConfig<any, any, any, TContext>,
@@ -47,7 +47,7 @@ export function resolveExternalValue<TContext>(
   }
 }
 
-function resolveExternalObject<TContext>(
+function resolveExternalObject<TContext extends Record<string, any>>(
   type: GraphQLCompositeType,
   object: any,
   unpathedErrors: Array<GraphQLError>,
@@ -91,7 +91,7 @@ function resolveExternalObject<TContext>(
   return mergeFields(mergedTypeInfo, object, subschema as Subschema, context, info);
 }
 
-function resolveExternalList<TContext>(
+function resolveExternalList<TContext extends Record<string, any>>(
   type: GraphQLList<any>,
   list: Array<any>,
   unpathedErrors: Array<GraphQLError>,
@@ -113,7 +113,7 @@ function resolveExternalList<TContext>(
   );
 }
 
-function resolveExternalListMember<TContext>(
+function resolveExternalListMember<TContext extends Record<string, any>>(
   type: GraphQLType,
   listMember: any,
   unpathedErrors: Array<GraphQLError>,

packages/links/src/linkToExecutor.ts

@@ -11,7 +11,9 @@ import {
 } from '@graphql-tools/utils';
 
 export function linkToExecutor(link: ApolloLink): Executor {
-  return function executorFromLink<TReturn, TArgs, TContext>(request: ExecutionRequest<TArgs, TContext>) {
+  return function executorFromLink<TReturn, TArgs extends Record<string, any>, TContext>(
+    request: ExecutionRequest<TArgs, TContext>
+  ) {
     const observable = execute(link, {
       query: request.document,
       operationName: request.operationName,

packages/loaders/git/src/parse.ts

@@ -1,9 +1,9 @@
-import { parseGraphQLSDL, parseGraphQLJSON, Source } from '@graphql-tools/utils';
+import { parseGraphQLSDL, parseGraphQLJSON, Source, GraphQLParseOptions } from '@graphql-tools/utils';
 
 /**
  * @internal
  */
-export function parse<T>({
+export function parse<T extends GraphQLParseOptions>({
   path,
   pointer,
   content,

packages/loaders/url/src/defaultAsyncFetch.ts

@@ -1,6 +1,6 @@
 import { fetch } from 'cross-undici-fetch';
 
 export type AsyncFetchFn = typeof fetch;
-export const defaultAsyncFetch: AsyncFetchFn = async (input: RequestInfo, init?: RequestInit): Promise<Response> => {
+export const defaultAsyncFetch: AsyncFetchFn = async (input, init) => {
   return fetch(input, init);
 };

packages/loaders/url/src/index.ts

@@ -505,7 +505,11 @@ export class UrlLoader implements Loader<LoadFromUrlOptions> {
       webSocketImpl
     );
 
-    return <TReturn, TArgs>({ document, variables, operationName }: ExecutionRequest<TArgs>) => {
+    return <TReturn, TArgs extends Record<string, any>>({
+      document,
+      variables,
+      operationName,
+    }: ExecutionRequest<TArgs>) => {
       return observableToAsyncIterable(
         subscriptionClient.request({
           query: document,