Feature/log4js

.gitignore

@@ -1,3 +1,4 @@
 node_modules/
 npm-debug.*
-dist/
+dist/
+logs/

.travis.yml

@@ -7,7 +7,6 @@ os:
 node_js:
   - 'node'
   - 'lts/*'
-  - '7'
   - '8'
 
 script:

README.md

@@ -36,14 +36,19 @@ npm start
 ## TODO
 
 - [x] [Redux](https://github.com/reduxjs/redux)-like style state manage
-- [ ] [Log4js](https://github.com/log4js-node/log4js-node)
+- [x] [Log4js](https://github.com/log4js-node/log4js-node)
 - [ ] [React-router](https://github.com/ReactTraining/react-router)
 - [ ] [Typescript](https://github.com/Microsoft/TypeScript)
-- [ ] [Webpack-v4](https://github.com/webpack/webpack)
+- [x] [Webpack-v4](https://github.com/webpack/webpack)
 - [ ] Test
 
 ## Changelog
 
+### [2.2.0] / 2019-03-26
+
+- Upgrade webpack to v4
+- Add logs using log4js
+
 ### [2.1.0] / 2018-12-11
 
 - Refactor Message.js with `useRef` and `useEffect`

conf/log.conf.js

@@ -0,0 +1,15 @@
+// documents https://log4js-node.github.io/log4js-node/dateFile.html
+module.exports = {
+  appenders: {
+    dateFile: {
+      type: 'dateFile',
+      filename: 'logs/chat.log',
+      pattern: 'yyyy-MM-dd', /* roll log in days */
+      daysToKeep: 30, /* keep log for 30 days */
+      layout: { type: 'json', separator: ',' }
+    }
+  },
+  categories: {
+    default: { appenders: ['dateFile'], level: 'trace' }
+  }
+}