als-send-file/lib/mw.js

file serving with advanced options for caching, headers, and error handling, compatible with Express middleware.

const fileHandler = require('./file-handler')
const optionsSchema = require('./options-schema')
const { isFunction, string } = require('als-schema')
const { join } = require('path')
function sendFileMw(root, httpErrorHandler, $options = {}) {
   root = string(3,255,join(__dirname,'..','..','..'))(root)
   httpErrorHandler = isFunction((res, code, msg) => { res.writeHead(code); res.end(msg); })(httpErrorHandler)
   const defaultOptions = optionsSchema.validate($options)
   return (req, res, next) => {
      res.sendFile = (filePath, options = defaultOptions, httpErrHandler = httpErrorHandler) => {
         options = optionsSchema.validate({ ...defaultOptions, ...options })
         filePath = join(root, filePath)
         return fileHandler(req, res, filePath, options, httpErrHandler)
      }
      next()
   }
}

module.exports = sendFileMw