feat(middleware): add support for Express

.npmignore

@@ -1,3 +1,4 @@
 *.spec.js
 node_modules
 .idea
+examples

README.md

@@ -5,7 +5,7 @@ Simple JSON logger middleware that combines the namespaces of [debug] and the
 
 It has the same logging levels as [bunyan].
 
-## Example
+## Example logging
 
 ```javascript
 process.env.DEBUG = 'redis';
@@ -29,7 +29,23 @@ will output
 {"name":"redis","action":"query","level":50,"time":"2016-08-15T08:50:23.569Z","error_name":"Error","error_stack":"Error: Unauthorized\n    at Object.<anonymous> (/home/blacksonic/workspace/bunyan-debug/example.js:15:32)\n    at Module._compile (module.js:541:32)\n    at Object.Module._extensions..js (module.js:550:10)\n    at Module.load (module.js:458:32)\n    at tryModuleLoad (module.js:417:12)\n    at Function.Module._load (module.js:409:3)\n    at Module.runMain (module.js:575:10)\n    at run (bootstrap_node.js:352:7)\n    at startup (bootstrap_node.js:144:9)\n    at bootstrap_node.js:467:3","error_message":"Unauthorized","problem":"missmatch"}
 ```
 
-Examples can be found in ```example.js```.
+Examples can be found in ```examples/index.js```.
+
+### Logging request identifier automatically
+
+The library provides middlewares for both Koa and Express applications.
+These middlewares add the request identifiers coming from the header X-Request-Id to every log 
+(in the log: `request_id`).
+
+```javascript
+const Koa = require('koa');
+const logFactory = require('@emartech/json-logger');
+
+app.use(logFactory.getMiddleware());
+```
+
+The method `getMiddleware` creates a Koa middleware (alias for `getKoaMiddleware`).
+The `getExpressMiddleware` method does the same, but returns an Express middleware.
 
 ## Development
 

examples/express.js

@@ -0,0 +1,22 @@
+'use strict';
+
+const express = require('express');
+const logFactory = require('../index');
+const logger = logFactory('example');
+const port = 3000;
+
+const app = express();
+
+app.use(logFactory.getExpressMiddleware());
+
+app.get('/', (req, res) => {
+  logger.info('before');
+
+  logFactory.setOnContext('customer_id', Math.round(Math.random() * 1000));
+
+  logger.info('after');
+  res.send('It works')
+});
+
+app.listen(port);
+console.log('listening on port: ' + port);

example.js → examples/index.js

@@ -1,7 +1,7 @@
 'use strict';
 
 process.env.DEBUG = 'redis';
-const logger = require('./index');
+const logger = require('../index');
 
 const mongoLogger = logger('mongo');
 const redisLogger = logger('redis');

koa-example.js → examples/koa.js

@@ -1,18 +1,12 @@
 'use strict';
 
 const Koa = require('koa');
-const uuid = require('uuid');
-const logFactory = require('./index');
+const logFactory = require('../index');
 const logger = logFactory('example');
 const port = 3000;
 
 const app = new Koa();
 
-app.use(async (ctx, next) => {
-  ctx.request.header['x-request-id'] = uuid.v4();
-  await next();
-});
-
 app.use(logFactory.getMiddleware());
 
 app.use(async (ctx) => {

index.js

@@ -19,7 +19,9 @@ logFactory.Logger = Logger;
 logFactory.getNamespaces = function() {
   return process.env.DEBUG || '';
 };
-logFactory.getMiddleware = contextMiddlewareFactory.getMiddleware.bind(contextMiddlewareFactory);
+logFactory.getKoaMiddleware = contextMiddlewareFactory.getKoaMiddleware.bind(contextMiddlewareFactory);
+logFactory.getExpressMiddleware = contextMiddlewareFactory.getExpressMiddleware.bind(contextMiddlewareFactory);
+logFactory.getMiddleware = logFactory.getKoaMiddleware;
 logFactory.setOnContext = contextMiddlewareFactory.setOnContext.bind(contextMiddlewareFactory);
 
 module.exports = logFactory;