feat(typescript-fetch): simplify response types

- avoid `Promise<Promise<T>>` / webstorm wanting to double `await`
  after latest updates

- reduce unnecessary noise in type hints, particularly in-editor
  tooltips, etc

Author: mnahkies

packages/documentation/src/pages/guides/concepts/servers-object-handling.mdx

@@ -95,7 +95,7 @@ export class ApiClient {
       .build(),
     timeout?: number,
     opts: RequestInit = {},
-  ): Promise<TypedFetchResponse<Res<202, void>>> {
+  ): Promise<Res<202, void>> {
     ...
   }
 }

packages/openapi-code-generator/src/typescript/typescript-fetch/typescript-fetch-client-builder.ts

@@ -15,7 +15,6 @@ export class TypescriptFetchClientBuilder extends TypescriptClientBuilder {
         "AbstractFetchClient",
         "Server",
         "Res",
-        "TypedFetchResponse",
         "StatusCode2xx",
         "StatusCode3xx",
         "StatusCode4xx",
@@ -112,7 +111,7 @@ export class TypescriptFetchClientBuilder extends TypescriptClientBuilder {
           default: "{}",
         },
       ],
-      returnType: `TypedFetchResponse<${returnType}>`,
+      returnType,
       body,
     })
   }

packages/typescript-fetch-runtime/src/joi.ts

@@ -1,5 +1,5 @@
 import type {Schema as JoiSchema} from "@hapi/joi"
-import type {Res, StatusCode, TypedFetchResponse} from "./main"
+import type {Res, StatusCode} from "./main"
 
 export function responseValidationFactory(
   possibleResponses: [string, JoiSchema][],
@@ -10,9 +10,9 @@ export function responseValidationFactory(
 
   // TODO: avoid any
   return async (
-    whenRes: TypedFetchResponse<Res<StatusCode, unknown>>,
+    whenRes: Promise<Res<StatusCode, unknown>>,
     // biome-ignore lint/suspicious/noExplicitAny: <explanation>
-  ): Promise<TypedFetchResponse<any>> => {
+  ): Promise<any> => {
     const res = await whenRes
 
     return {

packages/typescript-fetch-runtime/src/main.ts

@@ -26,15 +26,11 @@ export type StatusCode =
   | StatusCode4xx
   | StatusCode5xx
 
-export type Res<Status extends StatusCode, Type> = {
+export interface Res<Status extends StatusCode, JsonBody> extends Response {
   status: Status
-  json: () => Promise<Type>
+  json: () => Promise<JsonBody>
 }
 
-export type TypedFetchResponse<R extends Res<StatusCode, unknown>> = Promise<
-  Omit<Response, "json" | "status"> & R
->
-
 export type Server<T> = string & {__server__: T}
 
 export interface AbstractFetchClientConfig {
@@ -83,7 +79,7 @@ export abstract class AbstractFetchClient {
     url: string,
     opts: RequestInit,
     timeout: number | undefined = this.defaultTimeout,
-  ): TypedFetchResponse<R> {
+  ): Promise<R> {
     // main abort controller that will be returned to the caller
     const cancelRequest = new AbortController()
 
@@ -118,7 +114,7 @@ export abstract class AbstractFetchClient {
       }
       // if not aborted just throw
       throw err
-    }) as TypedFetchResponse<R>
+    }) as unknown as R
   }
 
   protected _query(params: QueryParams): string {

packages/typescript-fetch-runtime/src/zod.ts

@@ -1,5 +1,5 @@
 import type {z} from "zod"
-import type {Res, StatusCode, TypedFetchResponse} from "./main"
+import type {Res, StatusCode} from "./main"
 
 export function responseValidationFactory(
   possibleResponses: [string, z.ZodTypeAny][],
@@ -10,9 +10,9 @@ export function responseValidationFactory(
 
   // TODO: avoid any
   return async (
-    whenRes: TypedFetchResponse<Res<StatusCode, unknown>>,
+    whenRes: Promise<Res<StatusCode, unknown>>,
     // biome-ignore lint/suspicious/noExplicitAny: <explanation>
-  ): Promise<TypedFetchResponse<any>> => {
+  ): Promise<any> => {
     const res = await whenRes
 
     return {