From 85239bfdd309f3509140f76a5b3dd808320ba5a0 Mon Sep 17 00:00:00 2001
From: Yusuke Wada <yusuke@kamawada.com>
Date: Fri, 31 Jan 2025 14:31:05 +0900
Subject: [PATCH] fix(client): correct inferring empty object `c.json({})`

---
 src/client/client.test.ts | 12 ++++++++++++
 src/client/types.ts       | 15 +--------------
 2 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/src/client/client.test.ts b/src/client/client.test.ts
index 97292c736..69f59ca18 100644
--- a/src/client/client.test.ts
+++ b/src/client/client.test.ts
@@ -50,6 +50,7 @@ describe('Basic - JSON', () => {
     )
     .get('/hello-not-found', (c) => c.notFound())
     .get('/null', (c) => c.json(null))
+    .get('/empty', (c) => c.json({}))
 
   type AppType = typeof route
 
@@ -77,6 +78,9 @@ describe('Basic - JSON', () => {
     http.get('http://localhost/null', () => {
       return HttpResponse.json(null)
     }),
+    http.get('http://localhost/empty', () => {
+      return HttpResponse.json({})
+    }),
     http.get('http://localhost/api/string', () => {
       return HttpResponse.json('a-string')
     }),
@@ -139,6 +143,14 @@ describe('Basic - JSON', () => {
     expect(data).toBe(null)
   })
 
+  it('Should get a `{}` content', async () => {
+    const client = hc<AppType>('http://localhost')
+    const res = await client.empty.$get()
+    const data = await res.json()
+    expectTypeOf(data).toMatchTypeOf<{}>()
+    expect(data).toStrictEqual({})
+  })
+
   it('Should have correct types - primitives', async () => {
     const app = new Hono()
     const route = app
diff --git a/src/client/types.ts b/src/client/types.ts
index 29e5790e1..a7cbe2e6f 100644
--- a/src/client/types.ts
+++ b/src/client/types.ts
@@ -54,15 +54,6 @@ export type ClientRequest<S extends Schema> = {
       : {}
     : {})
 
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
-type BlankRecordToNever<T> = T extends any
-  ? T extends null
-    ? null
-    : keyof T extends never
-    ? never
-    : T
-  : never
-
 type ClientResponseOfEndpoint<T extends Endpoint = Endpoint> = T extends {
   output: infer O
   outputFormat: infer F
@@ -89,11 +80,7 @@ export interface ClientResponse<
   url: string
   redirect(url: string, status: number): Response
   clone(): Response
-  json(): F extends 'text'
-    ? Promise<never>
-    : F extends 'json'
-    ? Promise<BlankRecordToNever<T>>
-    : Promise<unknown>
+  json(): F extends 'text' ? Promise<never> : F extends 'json' ? Promise<T> : Promise<unknown>
   text(): F extends 'text' ? (T extends string ? Promise<T> : Promise<never>) : Promise<string>
   blob(): Promise<Blob>
   formData(): Promise<FormData>