From 36707163116874b7a2cd5a337cbee9832158f163 Mon Sep 17 00:00:00 2001
From: Yusuke Wada <yusuke@kamawada.com>
Date: Sun, 18 Aug 2024 18:22:30 +0900
Subject: [PATCH] feat(client): improve handling status code types

---
 src/client/types.test.ts | 67 ++++++++++++++++++++++++++++++++++++++++
 src/client/types.ts      | 24 ++++++++++----
 2 files changed, 85 insertions(+), 6 deletions(-)

diff --git a/src/client/types.test.ts b/src/client/types.test.ts
index 7619dabc..6cbd5d28 100644
--- a/src/client/types.test.ts
+++ b/src/client/types.test.ts
@@ -1,7 +1,12 @@
+/* eslint-disable @typescript-eslint/no-unused-vars */
 import { expectTypeOf } from 'vitest'
 import { Hono } from '..'
 import { upgradeWebSocket } from '../adapter/deno/websocket'
 import { hc } from '.'
+import { HTTPException } from '../http-exception'
+import type { Equal, Expect } from '../utils/types'
+import { setupServer } from 'msw/node'
+import { HttpResponse, http } from 'msw'
 
 describe('WebSockets', () => {
   const app = new Hono()
@@ -57,3 +62,65 @@ describe('with the leading slash', () => {
     expectTypeOf(client.foo[':id'].baz).toHaveProperty('$get')
   })
 })
+
+describe('Status Code - test only Types', () => {
+  const server = setupServer(
+    http.get('http://localhost/foo', async () => {
+      return HttpResponse.json({})
+    })
+  )
+
+  beforeAll(() => server.listen())
+  afterEach(() => server.resetHandlers())
+  afterAll(() => server.close())
+
+  const app = new Hono()
+  const flag = {}
+
+  const routes = app.get('/foo', (c) => {
+    if (flag) {
+      throw new HTTPException(500, {
+        message: 'Server Error!',
+      })
+    }
+    if (flag) {
+      return c.json({ message: 'invalid!' }, 401)
+    }
+    if (flag) {
+      return c.redirect('/', 301)
+    }
+    return c.json({ ok: true }, 200)
+  })
+
+  const client = hc<typeof routes>('http://localhost')
+
+  it('Should handle different status codes', async () => {
+    const res = await client.foo.$get()
+
+    if (res.status === 500) {
+      const data = await res.json<{ errorMessage: string }>()
+      type Expected = { errorMessage: string }
+      type verify = Expect<Equal<Expected, typeof data>>
+    }
+
+    if (res.status === 401) {
+      const data = await res.json()
+      type Expected = { message: string }
+      type verify = Expect<Equal<Expected, typeof data>>
+    }
+
+    if (res.status === 200) {
+      const data = await res.json()
+      type Expected = { ok: boolean }
+      type verify = Expect<Equal<Expected, typeof data>>
+    }
+  })
+
+  it('Should infer union types', async () => {
+    const res = await client.foo.$get()
+
+    const data = await res.json()
+    type Expected = { message: string } | { ok: boolean }
+    type verify = Expect<Equal<Expected, typeof data>>
+  })
+})
diff --git a/src/client/types.ts b/src/client/types.ts
index e64a98eb..33260981 100644
--- a/src/client/types.ts
+++ b/src/client/types.ts
@@ -1,6 +1,6 @@
 import type { Hono } from '../hono'
 import type { Endpoint, ResponseFormat, Schema } from '../types'
-import type { StatusCode, SuccessStatusCode } from '../utils/http-status'
+import type { RedirectStatusCode, StatusCode, SuccessStatusCode } from '../utils/http-status'
 import type { HasRequiredKeys } from '../utils/types'
 
 type HonoRequest = (typeof Hono.prototype)['request']
@@ -63,7 +63,15 @@ type ClientResponseOfEndpoint<T extends Endpoint = Endpoint> = T extends {
   outputFormat: infer F
   status: infer S
 }
-  ? ClientResponse<O, S extends number ? S : never, F extends ResponseFormat ? F : never>
+  ? F extends 'redirect'
+    ? ClientResponse<O, S extends RedirectStatusCode ? S : never, 'redirect'>
+    :
+        | ClientResponse<O, S extends StatusCode ? S : never, F extends ResponseFormat ? F : never>
+        | ClientResponse<
+            {},
+            S extends StatusCode ? Exclude<Exclude<StatusCode, RedirectStatusCode>, S> : never,
+            F extends ResponseFormat ? F : never
+          >
   : never
 
 export interface ClientResponse<
@@ -84,11 +92,13 @@ export interface ClientResponse<
   url: string
   redirect(url: string, status: number): Response
   clone(): Response
-  json(): F extends 'text'
+  json<JSONT>(): F extends 'text'
     ? Promise<never>
     : F extends 'json'
-    ? Promise<BlankRecordToNever<T>>
-    : Promise<unknown>
+    ? undefined extends JSONT
+      ? Promise<BlankRecordToNever<T>>
+      : Promise<JSONT>
+    : Promise<T & {}>
   text(): F extends 'text' ? (T extends string ? Promise<T> : Promise<never>) : Promise<string>
   blob(): Promise<Blob>
   formData(): Promise<FormData>
@@ -119,12 +129,14 @@ export type InferResponseType<T, U extends StatusCode = StatusCode> = InferRespo
   U
 >
 
+type WithoutEmptyObject<T> = T extends {} ? (keyof T extends never ? never : T) : T
+
 type InferResponseTypeFromEndpoint<T extends Endpoint, U extends StatusCode> = T extends {
   output: infer O
   status: infer S
 }
   ? S extends U
-    ? O
+    ? WithoutEmptyObject<O>
     : never
   : never