Versions 1.1.21 through 1.1.26 break end-to-end type safety with eden treaty

[lunarW1TCH]

What version of Elysia is running?

1.1.20 - 1.1.26

What platform is your computer?

Microsoft Windows NT 10.0.22631.0 x64

What steps can reproduce the bug?

Create an Elysia route with response validation:

new Elysia().post('', async () => { 
// ...
}, {
  response: {
    200: t.UnionEnum(['user has joined already', 'added free plan']),
    401: t.String(),
  },
  body: t.Object({
    agreedOnDataTerms: t.Boolean(),
  }),
})

Then create an eden treaty client for this route.

treaty<Route>(getBaseUrl()).index.post

What is the expected behavior?

This is the correct type output for versions 1.1.20 and below.

What do you see instead?

This is the type output for versions 1.1.21 through 1.1.26

Only the response is inferred incorrectly.

Additional information

I am using Elysia for Route Handlers in NextJS 15. Eden Treaty version is 1.1.3

Have you try removing the node_modules and bun.lockb and try again yet?

Yes, multiple times, tried different Elysia versions as well.

[jvidalv]

Same experience here, I use it with expo-router on an expo app.

Eden version "@elysiajs/eden": "1.1.3",, anything bigger than "elysia": "1.1.20", breaks types for async handlers.

Reproduction is simple, just slam an async on any route, types stop working, here is an example:

import { Elysia, t } from "elysia";

export const pokemons = new Elysia({ prefix: "/pokemons" }).get(
  "/",
  async () => {
    const pokemons = await fetch(
      "https://pokeapi.co/api/v2/pokemon/?limit=20&offset=20",
    );

    const response = (await pokemons.json()) as {
      results: { name: string; url: string }[];
    };

    return { success: true, message: response.results };
  },
  {
    response: t.Object({
      success: t.Boolean(),
      message: t.Array(
        t.Object({
          name: t.String(),
          url: t.String(),
        }),
      ),
    }),
  },
);

This works well on elysiajs 1.1.20 and treaty 1.1.3

[chayutzee]

Did you install @types/bun into project that want to use treaty ?
@lunarW1TCH @jvidalv

[lunarW1TCH]

I did not, I am using bun only as a dependency manager. Adding bun types breaks the app in multiple places.