ab-test-middleware/modules/middleware/DefaultDistributionMiddleware.js

An express middleware that manages multiple distributions for A/B/N testing purposes.

const path = require('path');
const express = require('express');
const fileExists = require("../lib/fileExists");

const defaultDistributionMiddleware = (req, res, next) => {
  try {
    const {
      distFolder, defaultDist, distPath, entryFile, ingresses, modifiedBaseUrl
    } = req.locals;
    if (!req.baseUrl || ingresses.includes(req.baseUrl)) {
      return res.sendFile(path.resolve(distFolder, defaultDist, entryFile));
    }
    const filePath = path.join(defaultDist, modifiedBaseUrl);
    if (fileExists(`${distPath}/${filePath}`)) {
      return res.sendFile(path.join(defaultDist, modifiedBaseUrl), { root: distPath, index: false });
    } else {
      next();
    }
  } catch (e) {
    return next(e);
  }
};

const createDefaultDistributionMiddleware = () => {
  const router = express.Router();
  router.use('*', defaultDistributionMiddleware);
  return router;
};

module.exports = { defaultDistributionMiddleware, createDefaultDistributionMiddleware };