Added SessionPluginExample sources

Author: nuxy

README.md

@@ -15,6 +15,7 @@ Collection of plugins for use in your [L³](https://github.com/lambda-lambda-lam
 | [ContentTypeJsonHeader](https://github.com/lambda-lambda-lambda/middleware/tree/master/plugins/ContentTypeJsonHeader) | Middleware to send JSON `Content-Type` header. |
 | [GoogleRecaptchaHandler](https://github.com/lambda-lambda-lambda/middleware/tree/master/plugins/GoogleRecaptchaHandler) | Middleware to validate [Google ReCAPTCHA invisible](https://developers.google.com/recaptcha/docs/invisible) responses. |
 | [PreflightOptionsHandler](https://github.com/lambda-lambda-lambda/middleware/tree/master/plugins/PreflightOptionsHandler) | Middleware to handle [preflight requests](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/OPTIONS). |
+| [SessionPluginExample](https://github.com/lambda-lambda-lambda/middleware/tree/master/plugins/SessionPluginExample) | Middleware example of validating a session that uses cookies. |
 | [SwaggerUIViewer](https://github.com/lambda-lambda-lambda/middleware/tree/master/plugins/SwaggerUIViewer) | Middleware to generate [Swagger UI](https://swagger.io/tools/swagger-ui) viewer. |
 
 ## Installation

plugins/SessionPluginExample/README.md

@@ -0,0 +1,45 @@
+# SessionPluginExample
+
+Middleware example of validating a session that uses cookies.
+
+## Installation
+
+See package [README](https://github.com/lambda-lambda-lambda/middleware#manual-installation) for instructions.
+
+### app.js
+
+```javascript
+const sessionPlugin = require(`${APP_ROOT}/middleware/SessionPluginExample`);
+
+router.use(sessionPlugin({
+  cookieName: 'SESSIONID',
+  validator: (token) => {
+
+    // Check token using conventional method; Return session values.
+    const customValidator = (token) => ({role: 'user', status: 'active', foo: 'bar'});
+    const sessionData = customValidator(token);
+
+    if (!sessionData) {
+      throw Error(`Invalid session: ${token}`);
+    }
+
+    return sessionData;
+  }
+}));
+```
+
+## Usage
+
+```javascript
+module.exports = (req, res) => {
+  const cookie = req.plugin('cookies');
+  // SESSIONID=<token>
+
+  const session = req.plugin('session');
+  // {role: 'user', status: 'active', foo: 'bar'}
+};
+```
+
+## References
+
+- [lambda-lambda-lambda](https://github.com/lambda-lambda-lambda)

plugins/SessionPluginExample/index.js

@@ -0,0 +1 @@
+module.exports = require('./src/plugin');

plugins/SessionPluginExample/src/plugin.js

@@ -0,0 +1,26 @@
+'use strict';
+
+const {RouterError} = require('@lambda-lambda-lambda/router/src/router/Error');
+
+/**
+ * Middleware example of validating a session that uses cookies.
+ *
+ * @requires CookieParserPlugin
+ */
+module.exports = ({cookieName, validator}) => {
+  return async (req, res, next) => {
+    if (cookieName && typeof validator === 'function') {
+      try {
+        const cookies = req.plugin('cookies');
+        const token = cookies[cookieName];
+        token && req.plugin('session', await validator(token));
+
+      } catch {
+        // Continue as "anonymous" user.
+      }
+
+    } else {
+      throw new RouterError('Invalid session options');
+    }
+  };
+};

plugins/SessionPluginExample/test/unit.js

@@ -0,0 +1,108 @@
+'use strict';
+
+const event          = require(`${PACKAGE_ROOT}/event.json`);
+const chai           = require('chai');
+const chaiAsPromised = require('chai-as-promised');
+
+chai.use(chaiAsPromised);
+
+const expect = chai.expect;
+
+// Load modules.
+const {
+  RouterError,
+  Request,
+  Response,
+  Stack,
+  Utils
+} = require('@lambda-lambda-lambda/router/exports');
+
+const middleware = require(PLUGIN_ROOT);
+
+describe('SessionPlugin', function() {
+  const stack = new Stack();
+
+  describe('success', function() {
+    const settings = {
+      cookieName: 'SESSIONID',
+      validator: (token) => ({role: 'user', status: 'active', foo: 'bar'})
+    };
+
+    const dependency = function(req, res, next) {
+      req.plugin('cookies', {[settings.cookieName]: 'abcdefghijklmnopqrstuvwxyz123456'});
+      next();
+    };
+
+    Utils.setFuncName(dependency, 'middleware');
+    Utils.setFuncName(middleware, 'middleware');
+
+    const route = async function(req, res, next) {
+      res.status(200).send();
+    };
+
+    Utils.setFuncName(route, 'route:index');
+
+    stack.middleware = [dependency, middleware(settings)];
+    stack.routes     = route;
+
+    // Define form POST parameters.
+    event.Records[0].cf.request.method = 'GET';
+    event.Records[0].cf.request.uri    = '/path/to/resource';
+    event.Records[0].cf.request.body   = {
+      data: Buffer.from('')
+        .toString('base64')
+    };
+
+    const req = new Request(event.Records[0].cf.request, {});
+    const res = new Response({});
+
+    stack.exec(req, res);
+
+    const result = res.data();
+
+    it('should not return headers', function() {
+      expect(result.headers).to.be.empty;
+    });
+
+    it('should return status', function() {
+      expect(result.status).to.equal(200);
+    });
+
+    it('should not return body', function() {
+      expect(result.body).to.be.undefined;
+    });
+  });
+
+  describe('error', function() {
+    const settings = {
+      cookieName: '',
+      validator: (token) => (true)
+    };
+
+    const dependency = function(req, res, next) {
+      req.plugin('cookies', {SESSIONID: 'abcdefghijklmnopqrstuvwxyz123456'});
+      next();
+    };
+
+    Utils.setFuncName(dependency, 'middleware');
+    Utils.setFuncName(middleware, 'middleware');
+
+    const route = async function(req, res, next) {
+      res.status(200).send();
+    };
+
+    Utils.setFuncName(route, 'route:index');
+
+    stack.middleware = [dependency, middleware(settings)];
+    stack.routes     = route;
+
+    const req = new Request(event.Records[0].cf.request, {});
+    const res = new Response({});
+
+    it('should throw RouterError', function() {
+      const result = stack.exec(req, res);
+
+      expect(result).to.be.rejectedWith(RouterError, /Invalid session options/);
+    });
+  });
+});