feat: NextJS EdgeRuntime support

Describe the feature you’d like to request

Since https://github.com/vercel/next.js/pull/39462 applied on NextJS 12.3.*'s EdgeRuntime, an internal server error occurs like below statement

ready - started server on 0.0.0.0:3000, url: http://localhost:3000
warn  - You have enabled experimental feature (runtime) in next.config.js.
warn  - Experimental features are not covered by semver, and may cause unexpected or broken application behavior. Use at your own risk.

warn  - You are using the experimental Edge Runtime with `experimental.runtime`.
event - compiled client and server successfully in 1406 ms (232 modules)
wait  - compiling / (client and server)...
event - compiled client and server successfully in 860 ms (385 modules)
[Error: A Node.js API is used (setImmediate) which is not supported in the Edge Runtime.
Learn more: https://nextjs.org/docs/api-reference/edge-runtime]
[Error: A Node.js API is used (setImmediate) which is not supported in the Edge Runtime.
Learn more: https://nextjs.org/docs/api-reference/edge-runtime]
wait  - compiling /api/trpc/[trpc] (client and server)...
wait  - compiling /_error (client and server)...
event - compiled client and server successfully in 318 ms (451 modules)
error - (middleware)/node_modules/.pnpm/@trpc+server@10.0.0-proxy-alpha.74/node_modules/@trpc/server/dist/adapters/next.mjs (11:0) @ getPath
error - Cannot read properties of undefined (reading 'trpc')
null
 [TRPCClientError: Unexpected token < in JSON at position 0] {
  meta: undefined,
  shape: undefined,
  data: undefined,
  name: 'TRPCClientError'
}

To Reproduce Error

1. Clone or run npx create-next-app --example https://github.com/trpc/trpc --example-path examples/next-minimal-starter trpc-minimal-starter
2. Enable EdgeRuntime with create next.config.js

module.exports = {
    experimental: {
        runtime: "experimental-edge",
      },
}

1. Run next dev

Describe the solution you’d like to see

TRPC can run well on NextJS EdgeRuntime. Maybe add some polyfill of setImmediate like https://github.com/YuzuJS/setImmediate/blob/master/setImmediate.js

Desribe alternate solutions

Additional information

https://github.com/vercel/next.js/issues/40457

👨‍👧‍👦 Contributing

• 🙋‍♂️ Yes, I’d be down to file a PR implementing this feature!

[sachinraja]

I tested it and it worked, try clearing .next.

[sachinraja]

You can’t pass a response object because tRPC needs to set the body of the response. You can set the response headers using the response returned from fetchRequestHandler.

And most NextJS 3rd party modules need to consume NextResponse as argument like https://github.com/vvo/iron-session.

You can also use the Response returned from fetchRequestHandler for this.