Type Error when trying to validate 'params' with zValidator - Types of parameters 'c' and 'c' are incompatible

[and-rose]

Type Error when trying to validate 'params' with zValidator - Types of parameters 'c' and 'c' are incompatible

[luukvhoudt]

Copy, pasting the following test from this repo into my project resulted in the same type error.

https://github.com/honojs/middleware/blob/main/packages/zod-validator/test/index.test.ts

I see we got one thing in common, I'm also using Bun for my project. Now using Bun v1.0.23 and Hono v3.12.4

[and-rose]

Yeah, I just tried pasting my code into the repo's test case using Node v18.17.0 and didn't get the type error. This looks like a bun specific thing for sure.

[luukvhoudt]

With the intention to create a new issue over at the Bun repository I was trying to create a minimal reproducible example. However, I didn't manage to trigger the error or I did managed to get it working without a type error.

These are the steps I followed:

1. bunx create-hono ./reproduction --template bun
2. cd reproduction/
3. bun add @hono/zod-validator zod
4. bun add --dev typescript
5. Change the src/index.ts:

   import { Hono } from 'hono'
   import { zValidator } from '@hono/zod-validator'
   import { z } from 'zod'
   
   const app = new Hono()
   
   app.get(
     '/', 
     zValidator('query', z.object({foo: z.string()})),
     (c) => c.text('Hello Hono!'),
   )
   
   export default app

6. Change the tsconfig.json:

   {
     "compilerOptions": {
       "target": "ES2022",
       "moduleResolution": "bundler",
       "esModuleInterop": true,
       "strict": true,
       "jsx": "react-jsx",
       "jsxImportSource": "hono/jsx"
     }
   }

7. bun --bun tsc

Maybe our projects have problematic settings in the tsconfig.json. I will get back to this issue some time later with the feedback of how this finding might have affected my project. Maybe I can figure out what setting caused the error.

[and-rose]

It might have something to do with adding the typescript dependency to the bun project? I couldn't 100% confirm that it's what helped but the second I ran bun add --dev typescript the error cleared from my project. Might be because the hono bun template doesn't have typescript in the package.json?

[yusukebe]

I can't reproduce it. No error occurs when I try @luukvhoudt's steps.

The error may occur if the hono files referenced by hono and @hono/zod-validator are different.

[and-rose]

I can confirm what fixed the issue on my WSL machine and MacOS was upgrading bun to v1.0.23 and rm -rf'ing my node_modules followed by a bun i

bun upgrade
rm -rf node_modules
bun i

You should be able to replicate the issue by downgrading back to v1.0.22 and reinstalling your node_modules. You can downgrade like this

curl -fsSl https://bun.sh/install | bash -s "bun-v1.0.22"

I'm happy to close this if this helps you guys too.

Edit:

Not too sure which one of the fixes specifically helped it but looks like bun had some peer dependency resolution fixes in 1.0.23.
https://bun.sh/blog/bun-v1.0.23