yarn-or-npm

Execute scripts with Yarn or npm.

yarn add -D yarn-or-npm
# or
npm i --save-dev yarn-or-npm

The client is determined by a series of ordered checks:

1. yarn.lock file is in the nearest package directory - yarn
2. package-lock.json file is in the nearest package directory - npm
3. yarn is installed - yarn
4. Fallback - npm

Module

import yarnOrNpm, { spawn, hasYarn, hasNpm } from 'yarn-or-npm';

// String of `yarn` or `npm` returned
console.log(yarnOrNpm());

// Boolean values for hasYarn, hasNpm
console.log(hasYarn());

// Spawn yarn or npm command
spawn(['init']);

// Spawn sync option
spawn.sync(['init'], { stdio: 'inherit' });

Under the covers, there are cached lookup values being used for efficiency. These can be manually cleared:

import yarnOrNpm from 'yarn-or-npm';
import { spawnSync } from 'child_process';

console.log(yarnOrNpm.hasYarn()); // false

spawnSync('npm', ['i', '-g', 'yarn'], { stdio: 'inherit' });

console.log(yarnOrNpm.hasYarn()); // false (cached)

yarnOrNpm.clearCache();
console.log(yarnOrNpm.hasYarn()); // true

CLI

yarn-or-npm <command>
# Can also use `yon` shorthand
yon <command>

Package

Modules with bin files can be called directly in package.json scripts:

{
  "devDependencies": {
    ...
    "yarn-or-npm": "^3.0.1"
  },
  "scripts": {
    "compile": "babel src --out-dir dist",
    "lint": "eslint .",
    "prepublish": "yarn-or-npm run lint && yarn-or-npm run compile"
  }
}