server.js

'use strict';

const hof = require('hof');
const config = require('./config.js');
const busboy = require('busboy');
const bl = require('bl');
const logger = require('hof/lib/logger')({ env: config.env });
const { sanitiseFilename } = require('./utils');

let settings = require('./hof.settings');

settings = Object.assign({}, settings, {
  behaviours: settings.behaviours.map(require),
  routes: settings.routes.map(require)
});

const app = hof(settings);

app.use((req, res, next) => {
  res.locals.htmlLang = 'en';
  next();
});

app.use((req, res, next) => {
  if (!req.is('multipart/form-data')) {
    next();
    return;
  }

  req.files = req.files || {};
  req.body = req.body || {};

  const bb = busboy({
    headers: req.headers,
    limits: {
      fileSize: config.upload.maxFileSizeInBytes
    }
  });

  bb.on('field', (key, value) => {
    req.body[key] = value;
  });

  bb.on('file', (key, file, fileInfo) => {
    logger.info(`Processing file: 
      filename: ${sanitiseFilename(fileInfo.filename)},
      encoding: ${fileInfo.encoding},
      mimeType: ${fileInfo.mimeType}`
    );

    if (!fileInfo.filename) {
      logger.warn(`File skipped due to missing filename for key: ${key}`);
      file.resume();
      return;
    }

    file.pipe(bl((err, data) => {
      if (err) {
        const errorMessage = `Failed to process file during streaming operation: ${err}`;
        logger.error(errorMessage);
        next(new Error(errorMessage));
        return;
      }

      const isDataEmpty = data.length === 0;

      if (isDataEmpty) {
        logger.error(`Empty file received, data length: ${data.length}, 
          filename: ${sanitiseFilename(fileInfo.filename)}`);
        next(new Error('Empty file received'));
        return;
      }

      req.files[key] = {
        data: file.truncated ? null : data,
        name: fileInfo.filename || null,
        encoding: fileInfo.encoding,
        mimetype: fileInfo.mimeType,
        truncated: file.truncated,
        size: Buffer.byteLength(data, 'binary')
      };
    }));
  });

  bb.on('error', err => {
    const errorMessage = `Error while parsing the form: ${err}`;
    logger.error(errorMessage);
    return next(new Error(errorMessage));
  });

  bb.on('finish', () => {
    next();
  });

  req.pipe(bb);
});

module.exports = app;