ESLint
ESLint
https://wohugb.gitbooks.io/javascript/content/tool/lintmd.html
用處:用來檢查code的語法
1.安裝
npm install -g eslint2.配置
於根目錄新增 .eslintrc.json{
"globals": {
// Put things like jQuery, etc
"jQuery": true,
"$": true
},
"env": {
// I write for browser
"browser": true,
// in CommonJS
"node": true
},
// To give you an idea how to override rule options:
"rules": {
// Tons of rules you can use, for example...
"quotes": [1, "double"]
}
}看到上面的rules的數字，對照下表，以上面為例，意思是對所有出現quotes(引號)的地方要使用double(兩個引號)，強制性為1(只產生警告訊息)
0 - Disable the rule
1 - Warn about the rule
2 - Throw error about the rule其他rules可參考官網
3.使用parser去解析ES6
npm install babel-eslint之後在.eslintrc.json加上
{
"parser": "babel-eslint",
"rules": {
...
}
}如何執行?
eslint 檔案名稱.js其他規則
{
"env": {
"browser": true,
"node": true,
"commonjs": true
},
"ecmaFeatures": {
// lambda表達式
"arrowFunctions": true,
// 解構賦值
"destructuring": true,
// class
"classes": true,
// http://es6.ruanyifeng.com/#docs/function#函數參數的默認值
"defaultParams": true,
// 塊級作用域，允許使用let const
"blockBindings": true,
// 允許使用模塊，模塊內默認嚴格模式
"modules": true,
// 允許字面量定義對像時，用表達式做屬性名
// http://es6.ruanyifeng.com/#docs/object#屬性名表達式
"objectLiteralComputedProperties": true,
// 允許對像字面量方法名簡寫
/*var o = {
method() {
return "Hello!";
}
};
等同於
var o = {
method: function() {
return "Hello!";
}
};
*/
"objectLiteralShorthandMethods": true,
/*
對像字面量屬性名簡寫
var foo = 'bar';
var baz = {foo};
baz // {foo: "bar"}
// 等同於
var baz = {foo: foo};
*/
"objectLiteralShorthandProperties": true,
// http://es6.ruanyifeng.com/#docs/function#rest參數
"restParams": true,
// http://es6.ruanyifeng.com/#docs/function#擴展運算符
"spread": true,
// http://es6.ruanyifeng.com/#docs/iterator#for---of循環
"forOf": true,
// http://es6.ruanyifeng.com/#docs/generator
"generators": true,
// http://es6.ruanyifeng.com/#docs/string#模板字符串
"templateStrings": true,
"superInFunctions": true,
// http://es6.ruanyifeng.com/#docs/object#對像的擴展運算符
"experimentalObjectRestSpread": true
},
"rules": {
// 定義對像的set存取器屬性時，強制定義get
"accessor-pairs": 2,
// 指定數組的元素之間要以空格隔開(,後面)， never參數：[ 之前和 ] 之後不能帶空格，always參數：[ 之前和 ] 之後必須帶空格
"array-bracket-spacing": [2, "never"],
// 在塊級作用域外訪問塊內定義的變量是否報錯提示
"block-scoped-var": 0,
// if while function 後面的{必須與if在同一行，java風格。
"brace-style": [2, "1tbs", { "allowSingleLine": true }],
// 雙峰駝命名格式
"camelcase": 2,
// 數組和對像鍵值對最後一個逗號， never參數：不能帶末尾的逗號, always參數：必須帶末尾的逗號，
// always-multiline：多行模式必須帶逗號，單行模式不能帶逗號
"comma-dangle": [2, "never"],
// 控制逗號前後的空格
"comma-spacing": [2, { "before": false, "after": true }],
// 控制逗號在行尾出現還是在行首出現
// http://eslint.org/docs/rules/comma-style
"comma-style": [2, "last"],
// 圈復雜度
"complexity": [2,9],
// 以方括號取對像屬性時，[ 後面和 ] 前面是否需要空格, 可選參數 never, always
"computed-property-spacing": [2,"never"],
// 強制方法必須返回值，TypeScript強類型，不配置
"consistent-return": 0,
// 用於指統一在回調函數中指向this的變量名，箭頭函數中的this已經可以指向外層調用者，應該沒卵用了
// e.g [0,"that"] 指定只能 var that = this. that不能指向其他任何值，this也不能賦值給that以外的其他值
"consistent-this": 0,
// 強制在子類構造函數中用super()調用父類構造函數，TypeScrip的編譯器也會提示
"constructor-super": 0,
// if else while for do後面的代碼塊是否需要{ }包圍，參數：
// multi 只有塊中有多行語句時才需要{ }包圍
// multi-line 只有塊中有多行語句時才需要{ }包圍, 但是塊中的執行語句只有一行時，
// 塊中的語句只能跟和if語句在同一行。if (foo) foo++; else doSomething();
// multi-or-nest 只有塊中有多行語句時才需要{ }包圍, 如果塊中的執行語句只有一行，執行語句可以零另起一行也可以跟在if語句後面
// [2, "multi", "consistent"] 保持前後語句的{ }一致
// default: [2, "all"] 全都需要{ }包圍
"curly": [2, "all"],
// switch語句強制default分支，也可添加 // no default 注釋取消此次警告
"default-case": 2,
// 強制object.key 中 . 的位置，參數:
// property，'.'號應與屬性在同一行
// object, '.' 號應與對像名在同一行
"dot-location": [2, "property"],
// 強制使用.號取屬性
// 參數： allowKeywords：true 使用保留字做屬性名時，只能使用.方式取屬性
// false 使用保留字做屬性名時, 只能使用[]方式取屬性 e.g [2, {"allowKeywords": false}]
// allowPattern: 當屬性名匹配提供的正則表達式時，允許使用[]方式取值,否則只能用.號取值 e.g [2, {"allowPattern": "^[a-z]+(_[a-z]+)+$"}]
"dot-notation": [2, {"allowKeywords": true}],
// 文件末尾強制換行
"eol-last": 2,
// 使用 === 替代 ==
"eqeqeq": [2, "allow-null"],
// 方法表達式是否需要命名
"func-names": 0,
// 方法定義風格，參數：
// declaration: 強制使用方法聲明的方式，function f(){} e.g [2, "declaration"]
// expression：強制使用方法表達式的方式，var f = function() {} e.g [2, "expression"]
// allowArrowFunctions: declaration風格中允許箭頭函數。 e.g [2, "declaration", { "allowArrowFunctions": true }]
"func-style": 0,
"generator-star-spacing": [2, { "before": true, "after": true }],
"guard-for-in": 0,
"handle-callback-err": [2, "^(err|error)$" ],
"indent": [2, 2, { "SwitchCase": 1 }],
"key-spacing": [2, { "beforeColon": false, "afterColon": true }],
"linebreak-style": 0,
"lines-around-comment": 0,
"max-nested-callbacks": 0,
"new-cap": [2, { "newIsCap": true, "capIsNew": false }],
"new-parens": 2,
"newline-after-var": 0,
"no-alert": 0,
"no-array-constructor": 2,
"no-caller": 2,
"no-catch-shadow": 0,
"no-cond-assign": 2,
"no-console": 0,
"no-constant-condition": 0,
"no-continue": 0,
"no-control-regex": 2,
"no-debugger": 2,
"no-delete-var": 2,
"no-div-regex": 0,
"no-dupe-args": 2,
"no-dupe-keys": 2,
"no-duplicate-case": 2,
"no-else-return": 0,
"no-empty": 0,
"no-empty-character-class": 2,
"no-empty-label": 2,
"no-eq-null": 0,
"no-eval": 2,
"no-ex-assign": 2,
"no-extend-native": 2,
"no-extra-bind": 2,
"no-extra-boolean-cast": 2,
"no-extra-parens": 0,
"no-extra-semi": 0,
"no-fallthrough": 2,
"no-floating-decimal": 2,
"no-func-assign": 2,
"no-implied-eval": 2,
"no-inline-comments": 0,
"no-inner-declarations": [2, "functions"],
"no-invalid-regexp": 2,
"no-irregular-whitespace": 2,
"no-iterator": 2,
"no-label-var": 2,
"no-labels": 2,
"no-lone-blocks": 2,
"no-lonely-if": 0,
"no-loop-func": 0,
"no-mixed-requires": 0,
"no-mixed-spaces-and-tabs": 2,
"no-multi-spaces": 2,
"no-multi-str": 2,
"no-multiple-empty-lines": [2, { "max": 1 }],
"no-native-reassign": 2,
"no-negated-in-lhs": 2,
"no-nested-ternary": 0,
"no-new": 2,
"no-new-func": 0,
"no-new-object": 2,
"no-new-require": 2,
"no-new-wrappers": 2,
"no-obj-calls": 2,
"no-octal": 2,
"no-octal-escape": 2,
"no-param-reassign": 0,
"no-path-concat": 0,
"no-process-env": 0,
"no-process-exit": 0,
"no-proto": 0,
"no-redeclare": 2,
"no-regex-spaces": 2,
"no-restricted-modules": 0,
"no-return-assign": 2,
"no-script-url": 0,
"no-self-compare": 2,
"no-sequences": 2,
"no-shadow": 0,
"no-shadow-restricted-names": 2,
"no-spaced-func": 2,
"no-sparse-arrays": 2,
"no-sync": 0,
"no-ternary": 0,
"no-this-before-super": 2,
"no-throw-literal": 2,
"no-trailing-spaces": 2,
"no-undef": 2,
"no-undef-init": 2,
"no-undefined": 0,
"no-underscore-dangle": 0,
"no-unexpected-multiline": 2,
"no-unneeded-ternary": 2,
"no-unreachable": 2,
"no-unused-expressions": 0,
"no-unused-vars": [2, { "vars": "all", "args": "none" }],
"no-use-before-define": 0,
"no-var": 0,
"no-void": 0,
"no-warning-comments": 0,
"no-with": 2,
"object-curly-spacing": 0,
"object-shorthand": 0,
"one-var": [2, { "initialized": "never" }],
"operator-assignment": 0,
"operator-linebreak": [2, "after", { "overrides": { "?": "before", ":": "before" } }],
"padded-blocks": 0,
"prefer-const": 0,
"quote-props": 0,
"quotes": [2, "single", "avoid-escape"],
"radix": 2,
"semi": [2, "never"],
"semi-spacing": 0,
"sort-vars": 0,
"space-after-keywords": [2, "always"],
"space-before-blocks": [2, "always"],
"space-before-function-paren": [2, "always"],
"space-in-parens": [2, "never"],
"space-infix-ops": 2,
"space-return-throw-case": 2,
"space-unary-ops": [2, { "words": true, "nonwords": false }],
"spaced-comment": [2, "always", { "markers": ["global", "globals", "eslint", "eslint-disable", "*package", "!"] }],
"strict": 0,
"use-isnan": 2,
"valid-jsdoc": 0,
"valid-typeof": 2,
"vars-on-top": 0,
"wrap-iife": [2, "any"],
"wrap-regex": 0,
"yoda": [2, "never"]
}
}使用sublime+ESLint
進入sublime的package manage(需先安裝)
輸入
SublimeLinter-eslint參考至 http://jonathancreamer.com/setup-eslint-with-es6-in-sublime-text/
Eslint React
npx eslint init然後安裝 vscode 的 eslint plugin
如果在vscode React 還是沒有顯示 syntax error線，可安裝
yarn add eslint-plugin-react如果還是在editor沒顯示紅線，則可開啟output查看錯誤
解法：
假設你有server跟frontend folder 開啟vscode時先進入client folder再開啟vscode，這樣才找得到路徑https://github.com/microsoft/vscode-eslint/issues/759#issuecomment-534958665
不要同時在local跟client都裝eslint 跟plugin
如果是mono repo 進入到你要做的專案在開啟VSCode
Last updated
