每天都有新鮮事

　　從昨天晚上開始認真看 webpack 得教學，花了半天多才漸漸理解如何使用，我果然還是不適合一開始就用官方文件來閱讀，還是找有教學的影片來看比較好吸收。


1.　套件安裝
　⊙　主要套件 : webpack
　⊙　ESLint 檢查: eslint eslint-loader
　⊙　Babel (ECMAScript6 語法轉換) : babel-core babel-loader babel-preset-es2015
　⊙　React 相關套件: react rect-dom jsx-loader eslint-plugin-react babel-preset-react

　packages.json 大致上會如下：

{

  "name": "sample",

  "version": "1.0.0",

  "description": "",

  "main": "webpack.config.js",

  "dependencies": {

    "jsx-loader": "^0.13.2",

    "webpack": "^1.12.14"

  },

  "devDependencies": {

    "babel-core": "^6.7.4",

    "babel-loader": "^6.2.4",

    "babel-preset-es2015": "^6.6.0",

    "babel-preset-react": "^6.5.0",

    "eslint": "^2.7.0",

    "eslint-loader": "^1.3.0",

    "eslint-plugin-react": "^4.2.3",

    "react": "^0.14.8",

    "react-dom": "^0.14.8"

  },

  "scripts": {

    "test": "echo \"Error: no test specified\" && exit 1"

  },

  "author": "",

  "license": "ISC"

}

2. webpack.config.js 設定檔
　⊙　目前就只測試到基本的 eslint 檢查，可用 .jsx 副檔名

module.exports = {

    entry: ['./assets/jsx/app'],

    output: {

        path: 'public/js/',

        filename: 'bundle.js'

    },

    resolve: {

        extensions: ['', '.js', '.jsx']

    },

    module: {

        preLoaders: [

            {

                test: /\.jsx$/,

                exclude: /node_modules/,

                loader: 'eslint-loader'

            }

        ],

        loaders: [

            {

                test: /\.js|jsx$/,

                exclude: /node_modules/,

                loader: 'babel-loader',

                query:{

                    "presets": ["es2015", "react"]

                }

            }

        ]

    }

}

3. ESLint 設定
　⊙　套件安裝
sudo npm install -g eslint

　⊙　產生基本設定檔，eslint --init，可參考下面回答

? How would you like to configure ESLint? Answer questions about your style
? Are you using ECMAScript 6 features? Yes
? Are you using ES6 modules? Yes
? Where will your code run? Browser
? Do you use CommonJS? Yes
? Do you use JSX? Yes
? Do you use React Yes
? What style of indentation do you use? Spaces
? What quotes do you use for strings? Single
? What line endings do you use? Unix
? Do you require semicolons? Yes
? What format do you want your config file to be in? JSON


　⊙　加上 React 檢查套件 npm install --save-dev eslint-plugin-react
　　　* extends 裡加上 `plugin:react/recommended` ，額外用別人寫好的檢查套件
　　　　　* 可避免 import module 後，出現未使用變數的問題
　　　　　* 若要使用`dangerouslySetInnerHTML`這語法，需在 rules 內加上 `"react/no-danger": 0`
　　　* jQuery 可在 env 內加上來略過錯誤
　　　* 全域變數請另外寫 globals 來略過檢查

{

    "env": {

        "browser": true,

        "commonjs": true,

        "es6": true,

        "jquery": true

    },

    "extends": ["eslint:recommended", "plugin:react/recommended"],

    "parserOptions": {

        "ecmaFeatures": {

            "experimentalObjectRestSpread": true,

            "jsx": true

        },

        "sourceType": "module"

    },

    "plugins": [

        "react"

    ],

    "rules": {

        "indent": [

            "error",

            4

        ],

        "linebreak-style": [

            "error",

            "unix"

        ],

        "quotes": [

            "error",

            "single"

        ],

        "semi": [

            "error",

            "always"

        ],

        "react/no-danger": 0,

        "no-console": ["error", { "allow": ["log", "warn", "error"] }]

    },

    "globals": {

	    "socket": true,

	    "eventEmitter": true

    }

}