app.engine('html', require('express-posthtml'))

app.set('view options', { plugins: [], options: {} })

res.render('file.ext')

app.set('view options', { options: { parser: pug }})

res.render('file.pug', { plugins: [...plugins] })

app.set('view options', { plugins: [...plugins], options: {} })

res.render('file', { plugins: [/* PostHTML Plugins */], extend: true })

import express from 'express'
import posthtml from 'express-posthtml'
const app = express()
app.engine('html', posthtml)
const plugins = [
  require('posthtml-bem')(),
  require('posthtml-expressions')()
]
const options = {}
app.set('views', /* Path to views */)
app.set('view options', { plugins: plugins, options: options })
app.get('/', (req, res) => res.render('index.html'))
app.listen(3000)