(bug): Usng hono/cache breaks types for c.env in Hono 3.6.0

[AdiRishi]

What version of Hono are you using?

3.6.0

What runtime/platform is your app running on?

Cloudflare Workers

What steps can reproduce the bug?

1. In CF workers, add a few types to the Env interface for workers. E.g

   export type Env = {
   R2_STORE: R2Bucket;
   };

2. Create a new app instance of Hono with proper env bindings. E.g

   export const app = new Hono<{ Bindings: Env; }>();

3. Setup a route using one of those bindings. E.g

   app.get('/bucket-get', async (c) => {
   // the type of R2_BUCKET is R2Bucket (correct)
   const value = await c.env.R2_BUCKET.get('example.jpg');
   return c.json({ value });
   });

4. Add the cache middleware to the route. E.g

   app.get(
   '/bucket-get',
   cache({
   cacheName: 'r2-artifacts',
   wait: false,
   cacheControl: 'max-age=86400, stale-while-revalidate=3600',
   }),
   async (c) => {
   // the type of R2_BUCKET is now any
   const value = await c.env.R2_BUCKET.get('example.jpg');
   return c.json({ value });
   });

What is the expected behavior?

The type of c.env.R2_BUCKET should be R2Bucket

What do you see instead?

The type of c.env.R2_BUCKET is any because the type of c.env is now any

Additional information

If a reproduction repository helps, you can check the renovate/hono-3.x branch on https://github.com/AdiRishi/turborepo-remote-cache-cloudflare

To setup the repository, just clone it and run yarn install, the specific line which can showcase this error is at https://github.com/AdiRishi/turborepo-remote-cache-cloudflare/blob/renovate/hono-3.x/src/routes/v8/artifacts.ts#L62

[AdiRishi]

Hey @yusukebe

I just tried the fix you pushed in 3.6.1 and it does fix the reported problem 🎉 .

Unfortunately I found a few new type errors that still exist in 3.6.1, I'll list them below, but let me know if you want me to open a new issue to deal with them

Code example:

import { middleware } from 'hono/factory'; // import for the second code block (attempted re-write)
export const internalRouter = new Hono<{ Bindings: Env }>();

// Old code before 3.6.x
// This used to work, but the middleware(c,next) line throws an error as it doesn't like the type of c anymore
// internalRouter.use('*', async (c, next) => {
//   const middleware = bearerAuth({ token: c.env.TURBO_TOKEN });
//   await middleware(c, next);
// });

// I tried to re-write this using the new middleware helper you made, but it also has a type error
internalRouter.use(
  '*',
  middleware(async (c, next) => {
    const authMiddleware = bearerAuth({ token: c.env?.TURBO_TOKEN });
    await authMiddleware(c, next);
  })
);

In the re-write I tied with the new middleware helper, the type of c.env doesn't seem to properly contain the Env type that I'm passing in? E.g c.env.TURBO_TOKEN is of type unknown.

[yusukebe]

@AdiRishi

Hi! That issue might be fixed in v3.6.2 released now. Try it!

[AdiRishi]

Just updated to 3.6.3 and everything is working great, than you 🚀

[yusukebe]

Nice!