Require IIFEs to be Wrapped (wrap-iife)

需要把立即执行的函数包裹起来 (wrap-iife)

The --fix option on the command line can automatically fix some of the problems reported by this rule.

命令行中的 --fix 选项可以自动修复一些该规则报告的问题。

You can immediately invoke function expressions, but not function declarations. A common technique to create an immediately-invoked function expression (IIFE) is to wrap a function declaration in parentheses. The opening parentheses causes the contained function to be parsed as an expression, rather than a declaration.

你可以立即调用函数表达式，而不是函数声明。创建一个立即执行函数 (IIFE) 的一个通用技术是用括号包裹一个函数声明。括号内的函数被解析为一个表达式，而不是一个声明。

// function expression could be unwrapped
var x = function () { return { y: 1 };}();

// function declaration must be wrapped
function () { /* side effects */ }(); // SyntaxError

Rule Details

This rule requires all immediately-invoked function expressions to be wrapped in parentheses.

该规则要求所有的立即执行函数表达式使用括号包裹起来。

Options

This rule has two options, a string option and an object option.

该规则有两个选项，一个是字符串，一个是对象。

String option:

字符串选项：

"outside" enforces always wrapping the call expression. The default is "outside".
"outside" 强制总是包裹 call 表达式。默认是 "outside"。
"inside" enforces always wrapping the function expression.
"inside" 强制总是包裹 function 表达式。
"any" enforces always wrapping, but allows either style.
"any"强制总是包裹，但允许其它风格。

Object option:

对象选项：

"functionPrototypeMethods": true additionally enforces wrapping function expressions invoked using .call and .apply. The default is false.
"functionPrototypeMethods": true 使用 .call 和 .apply 调用时，强制要求包裹函数表达式。默认为 false。

outside

Examples of incorrect code for the default "outside" option:

默认选项 "outside" 的错误代码示例：

/*eslint wrap-iife: ["error", "outside"]*/

var x = function () { return { y: 1 };}(); // unwrapped
var x = (function () { return { y: 1 };})(); // wrapped function expression

Examples of correct code for the default "outside" option:

默认选项 "outside" 的正确代码示例：

/*eslint wrap-iife: ["error", "outside"]*/

var x = (function () { return { y: 1 };}()); // wrapped call expression

inside

Examples of incorrect code for the "inside" option:

选项 "inside" 的错误代码示例：

/*eslint wrap-iife: ["error", "inside"]*/

var x = function () { return { y: 1 };}(); // unwrapped
var x = (function () { return { y: 1 };}()); // wrapped call expression

Examples of correct code for the "inside" option:

选项 "inside" 的正确代码示例：

/*eslint wrap-iife: ["error", "inside"]*/

var x = (function () { return { y: 1 };})(); // wrapped function expression

any

Examples of incorrect code for the "any" option:

选项 "any" 的错误代码示例：

/*eslint wrap-iife: ["error", "any"]*/

var x = function () { return { y: 1 };}(); // unwrapped

Examples of correct code for the "any" option:

选项 "any" 的正确代码示例：

/*eslint wrap-iife: ["error", "any"]*/

var x = (function () { return { y: 1 };}()); // wrapped call expression
var x = (function () { return { y: 1 };})(); // wrapped function expression

functionPrototypeMethods

Examples of incorrect code for this rule with the "inside", { "functionPrototypeMethods": true } options:

选项 "inside", { "functionPrototypeMethods": true } 的错误代码示例：

/* eslint wrap-iife: [2, "inside", { functionPrototypeMethods: true }] */

var x = function(){ foo(); }()
var x = (function(){ foo(); }())
var x = function(){ foo(); }.call(bar)
var x = (function(){ foo(); }.call(bar))

Examples of correct code for this rule with the "inside", { "functionPrototypeMethods": true } options:

选项 "inside", { "functionPrototypeMethods": true } 的正确代码示例：

/* eslint wrap-iife: [2, "inside", { functionPrototypeMethods: true }] */

var x = (function(){ foo(); })()
var x = (function(){ foo(); }).call(bar)

Version

This rule was introduced in ESLint 0.0.9.

该规则在 ESLint 0.0.9 中被引入。