kohkimakimoto/nightmare repository overview

nightmare() {
    docker run -v $PWD:/mnt/work -w /mnt/work --rm -e "cmd=$NIGHTMARE_CMD" kohkimakimoto/nightmare:latest "$@";
    return $?;
}

var Nightmare = require('nightmare');
var nightmare = Nightmare({ show: false });

nightmare
  .goto("https://google.com")
  .evaluate(() => {
    const body = document.querySelector('body');

    return {
      height: body.scrollHeight,
      width: body.scrollWidth
    };
  })
  .then(function(dimensions) {
    return nightmare
      .viewport(dimensions.width, dimensions.height)
      .wait(1000)
      .screenshot(require('path').join(__dirname, 'screenshot.png'))
  })
  .then(function() {
    nightmare.end(function() {
      console.log('done');
    });
  });

$ nightmare screenshot.js