fix(client): infer null correctly (#2469)

* fix(client): infer `null` correctly

* denoify

deno_dist/client/types.ts

@@ -43,7 +43,13 @@ export type ClientRequest<S extends Schema> = {
 }
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-type BlankRecordToNever<T> = T extends any ? (keyof T extends never ? never : T) : never
+type BlankRecordToNever<T> = T extends any
+  ? T extends null
+    ? null
+    : keyof T extends never
+    ? never
+    : T
+  : never
 
 export interface ClientResponse<T> {
   readonly body: ReadableStream | null

src/client/client.test.ts

@@ -48,6 +48,7 @@ describe('Basic - JSON', () => {
       }
     )
     .get('/hello-not-found', (c) => c.notFound())
+    .get('/null', (c) => c.json(null))
 
   type AppType = typeof route
 
@@ -69,6 +70,9 @@ describe('Basic - JSON', () => {
     }),
     rest.get('http://localhost/hello-not-found', (_req, res, ctx) => {
       return res(ctx.status(404))
+    }),
+    rest.get('http://localhost/null', (_req, res, ctx) => {
+      return res(ctx.status(200), ctx.json(null))
     })
   )
 
@@ -111,6 +115,14 @@ describe('Basic - JSON', () => {
     const res = await client['hello-not-found'].$get()
     expect(res.status).toBe(404)
   })
+
+  it('Should get a `null` content', async () => {
+    const client = hc<AppType>('http://localhost')
+    const res = await client.null.$get()
+    const data = await res.json()
+    expectTypeOf(data).toMatchTypeOf<null>()
+    expect(data).toBe(null)
+  })
 })
 
 describe('Basic - query, queries, form, path params, header and cookie', () => {

src/client/types.ts

@@ -43,7 +43,13 @@ export type ClientRequest<S extends Schema> = {
 }
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-type BlankRecordToNever<T> = T extends any ? (keyof T extends never ? never : T) : never
+type BlankRecordToNever<T> = T extends any
+  ? T extends null
+    ? null
+    : keyof T extends never
+    ? never
+    : T
+  : never
 
 export interface ClientResponse<T> {
   readonly body: ReadableStream | null