Yarn Workspace

.
├── apps
│   └── fizzbuzz
│       ├── package.json
│       └── src
│           └── index.ts
├── biome.json
├── package.json
├── packages
│   └── fizzbuzz
│       ├── package.json
│       └── src
│           └── index.ts
└── yarn.lock

package.json

package.json

{
  "name": "yarn-workspace-tsx-test",
  "private": true,
  "scripts": {
    "fmt": "yarn biome format --write ./"
  },
  "workspaces": ["apps/*", "packages/*"],
  "devDependencies": {
    "@biomejs/biome": "^1.9.4",
    "tsx": "^4.19.1"
  }
}

apps

package.json

WARNING

 Yarnを使用してMonorepoを構築する際、各パッケージのpackage.jsonにversionフィールドが指定されていないと、他のパッケージからそのパッケージをインポートできない。

apps/fizzbuzz/package.json

{
  "name": "@apps/fizzbuzz",
  "version": "1.0.0",
  "private": "true",
  "dependencies": {
    "@packages/fizzbuzz": "1.0.0"
  }
}

TypeScript

apps/fizzbuzz/src/index.ts

import { fizzBuzz } from '@packages/fizzbuzz'

console.log('Hello World!')
console.log(fizzBuzz(100))

packages

package.json

packages/fizzbuzz/package.json

{
    "name": "@packages/fizzbuzz",
    "version": "1.0.0",
    "private": "true",
    "main": "src/index.ts"
}

TypeScript

packages/fizzbuzz/src/index.ts

export const fizzBuzz = (number: number): string => {
  if (number % 15 === 0) return 'FizzBuzz'
  if (number % 3 === 0) return 'Fizz'
  if (number % 5 === 0) return 'Buzz'
  return number.toString()
}

Execution

yarn

yarn install
yarn tsx watch apps/fizzbuzz/src/index.ts
Hello World!
Buzz