default error type

Author: ajaishankar

src/types.ts

@@ -69,10 +69,10 @@ type _OpErrorType<T> = {
 
 type Coalesce<T, D> = [T] extends [never] ? D : T
 
-// coalesce default error type to unknown
+// coalesce default error type
 export type OpErrorType<OP> = Coalesce<
   _OpErrorType<OpResponseTypes<OP>>,
-  unknown
+  { status: number; data: any }
 >
 
 export type CustomRequestInit = Omit<RequestInit, 'headers'> & {

test/fetch.test.ts

@@ -142,6 +142,21 @@ describe('fetch', () => {
       other: true,
     })
   })
+  it('default error type {status: number, data: any}', async () => {
+    expect.assertions(2)
+
+    const fun = fetcher.path('/defaulterror').method('get').create()
+
+    try {
+      await fun({})
+    } catch (e) {
+      if (e instanceof fun.Error) {
+        const error = e.getActualType()
+        expect(error.status).toBe(500)
+        expect(error.data).toEqual('internal server error')
+      }
+    }
+  })
 
   it('network error', async () => {
     expect.assertions(1)

test/mocks/handlers.ts

@@ -61,6 +61,9 @@ const methods = {
           )
         : res(ctx.status(status))
     }),
+    rest.get(`${HOST}/defaulterror`, (req, res, ctx) => {
+      return res(ctx.status(500), ctx.body('internal server error'))
+    }),
     rest.get(`${HOST}/networkerror`, (req, res) => {
       return res.networkError('failed to connect')
     }),

test/paths.ts

@@ -1,3 +1,4 @@
+/* eslint-disable @typescript-eslint/ban-types */
 export type Data = {
   params: string[]
   headers: Record<string, string>
@@ -65,9 +66,14 @@ export type paths = {
       }
     }
   }
+  '/defaulterror': {
+    get: {
+      parameters: {}
+      responses: {}
+    }
+  }
   '/networkerror': {
     get: {
-      // eslint-disable-next-line @typescript-eslint/ban-types
       parameters: {}
       responses: {
         default: string