I am trying to implement Rollup and Typescript for a monorepo. I am running into a problem where I am getting Typescript issues from dependancies which they themselves are projects within the monorepo. I am using pnpm and Lerna to manage my monorepo. It seems like rollup is attempting to run against the modules for project-b even though they are coming from node_modules.

I would provide code, but I would have to write a lot of it. I have created a repo in GitHub which reproduces the problem.

There is a README in this repo with the steps to reproduce the issue.

https://github.com/CodeMedic42/rollup-issue/tree/main

I will, however, provide the Rollup config and the TypeScript config that I have using.

Rollup

import { defineConfig } from 'rollup';
import path from 'path';
import pluginTs from '@rollup/plugin-typescript';

export default defineConfig([
  {
    input: path.join(process.cwd(), 'src/index.ts'),
    output: [
      {
        dir: 'dist',
        format: 'es',
        entryFileNames: '[name].mjs',
        preserveModules: true,
        sourcemap: true,
      },
    ],
    plugins: [
      pluginTs(),
    ],
  },
])

Typescript

{
  "compilerOptions": {
    "target": "es2020",
    "lib": ["ES2020", "DOM", "DOM.Iterable"],
    "module": "ES2020",
    "moduleResolution": "Bundler",
    "jsx": "react-jsx",
    "baseUrl": "./src",
    "noEmit": true,
    "isolatedModules": true,
    "esModuleInterop": true,
    "strict": true,
    "checkJs": true
  },
  "exclude": [
    "dist/**/*",
    "node_modules/**/*"
  ]
}