(be sure to run npm install to install those tasty dependencies!)

index.js

const babel = require('@babel/core')
const fs = require('fs')

let file = process.argv.slice(2)[0]
let text = file

if (fs.existsSync(file)) {
  text = fs.readFileSync(file).toString()
}

console.log(
  babel.transform(
    text,
    {
      plugins: [
        require.resolve('@babel/plugin-transform-template-literals'),
      ]
    }
  ).code
)

package.json

{
  "name": "babel",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@babel/core": "^7.7.7",
    "@babel/plugin-transform-template-literals": "^7.7.4"
  }
}

test.js

`1 + 1 = ${1 + 1}`