Convert .eml file to .html with node

eml-to-html.js

const EmlParser = require('eml-parser');
const fs = require('fs');

const inputFile = process.argv[2];

if (!inputFile) throw new Error("Missing input file path argument");
if (!inputFile.match(/\.eml$/)) throw new Error("Only .eml files supported");
if (!fs.existsSync(inputFile)) throw new Error(`Couldn't find file ${inputFile}`);

const emailFile = fs.createReadStream(inputFile);

new EmlParser(emailFile)
  .getEmailAsHtml()
  .then(htmlString => {
    process.stdout.write(htmlString);
  })
  .catch(error => { console.log(error) });