Summary

I know this is not really in Turborepo's purview but I am wondering if anyone can give me some help on resolving RPC methods.

I have a microservice architecture with several cloudflare workers communicating over RPC. At this time, wrangler (Cloudflare CLI) does not generate types for RPC methods. There is a workaround which helps with IDE inference but tsc will still try and check types outside of the specified directory.

Example

Let's say I have 2 cloudflare workers in the /apps directory.

Worker 1 can expose an add method:

import { WorkerEntrypoint } from "cloudflare:workers";

export default class extends WorkerEntrypoint {
  add(a, b) {
    return a + b;
  }
}

Worker 2 can call it like a regular function even though it executes on Worker 1:

export default {
  async fetch(request, env) {
    const result = await env.WORKER_1.add(1, 2);
    return new Response(result);
  },
};

Problem is I want to have type inference without manually typing params and responses. There is a current workaround to extend the Cloudflare Env object like this:

// Worker 2's extended-env.d.ts
interface ExtendedEnv extends Env {
	WORKER_1: Service<import("../worker-1/src/index.js").default>;
}

Then in Worker 2's index, we can add the new ExtendedEnv interface:

export default {
  async fetch(request, env: ExtendedEnv) {
    const result = await env.WORKER_2.add(1, 2);
    return new Response(result);
  },
};

This works for my IDE but I cannot get it working with the TS compiler. If I run tsc --noEmit in Worker 2, I will get something like:

../worker-1/src/index.ts:34:25 - error TS2339: Property 'EXAMPLE_VAR' does not exist on type 'ExtendedEnv'.

Note: EXAMPLE_VAR exists on Worker 1 but not Worker 2 (this should be checked on Worker 1 and not worker 2).

Worker 2 tsconfig.json

{
	"extends": "@repo/typescript-config/worker.json",
	"compilerOptions": {
		"outDir": "dist",
		"types": ["./extended-env.d.ts"]
	},
	"include": ["worker-configuration.d.ts", "src", "extended-env.d.ts"],
	"exclude": ["test", "node_modules", "../worker-1/**"]
}

Base json.config:

{
	"$schema": "https://json.schemastore.org/tsconfig",
	"extends": "./base.json",
	"display": "Worker",
	"compilerOptions": {
		"target": "ESNext",
		"lib": ["ESNext"],
		"module": "ESNext",
		"moduleResolution": "Bundler",
		"resolveJsonModule": true,
		"allowJs": true,
		"checkJs": false,
		"noEmit": true,
		"isolatedModules": true,
		"allowSyntheticDefaultImports": true,
		"forceConsistentCasingInFileNames": true,
		"strict": true,
		"skipLibCheck": true
	}
}

Additional information

Others in the discussion seemed to get it working but I had no luck. Also important to note that I do not have a root tsconfig.