env-robotstxt

Feature

Set env variable to generate robots.txt file
Generate Disallow: / by default (without env variable)
Allow generate in to different folder
Easy to config robots.txt if you use git (different branch different robots content)
For all static website projects, like html, vue, react, angular, php, etc.

 npm install env-robotstxt 
 # or 
 yarn add env-robotstxt

Add the robot (or your preferred command) command in scripts object:

"scripts": {
    "robot": "npx env-robotstxt"   // default
  },

"scripts": {
    "robot": "npx env-robotstxt dist"   // generate into `dist` folder
  },

then set up the env variable ENV_ROBOTS_CONTENT:

ENV_ROBOTS_CONTENT="User-agent: *\nDisallow: \nSitemap: https://domain.name/sitemap.xml"

npm run robot
or 
yarn robot