Improve ExpressJS support

src/index.js

@@ -3,8 +3,7 @@ const ruleChecker = require('./rule-checker');
 const jwtDecode = require('./jwt-decode');
 const denyNotAllowed = require('./deny-not-allowed');
 
-module.exports = (configs, options = {}) => function () {
-  const app = this;
+module.exports = (configs, options = {}) => function (app = this) {
   const check = ruleChecker(options);
 
   if (options.jwt) app.use(jwtDecode(options.jwt));

test/unit/express.test.js

@@ -0,0 +1,28 @@
+const test = require('ava');
+const lib = require('../../src');
+const Supertest = require('supertest');
+const express = require('express');
+
+const app = express();
+
+test('should work for express', async (t) => {
+  const config = [{ url: '/blog', method: 'GET', allow: {} }];
+  const options = { denyNotAllowed: true };
+
+  lib(config, options)(app);
+  app.get('/blog', (req, res) => {
+    res.send({ message: 'hi' });
+  });
+
+  app.get('/secret', (req, res) => {
+    res.send({ message: 'secret' });
+  });
+
+  const supertest = Supertest(app);
+
+  const { error: getBlogError } = await supertest.get('/blog');
+  t.falsy(getBlogError);
+
+  const { error: getSecretError } = await supertest.get('/secret');
+  t.truthy(getSecretError);
+});