Disallow empty destructuring patterns (no-empty-pattern)

禁止使用空解构模式 (no-empty-pattern)

When using destructuring, it’s possible to create a pattern that has no effect. This happens when empty curly braces are used to the right of an embedded object destructuring pattern, such as:

当使用解构赋值时,可能创建了一个不起作用的模式。把空的花括号放在嵌入的对象的解构模式右边时,就会产生这种情况,例如:

// doesn't create any variables
var {a: {}} = foo;

In this code, no new variables are created because a is just a location helper while the {} is expected to contain the variables to create, such as:

在以上代码中,没有创建新的变量,因为 a 只是一个辅助位置,而 {} 将包含创建的变量,例如:

// creates variable b
var {a: { b }} = foo;

In many cases, the empty object pattern is a mistake where the author intended to use a default value instead, such as:

在许多情况下,作者本来打算使用一个默认值,却错写成空对象,例如:

// creates variable a
var {a = {}} = foo;

The difference between these two patterns is subtle, especially because the problematic empty pattern looks just like an object literal.

这两种模式直接的区别是微妙的,因为空模式看起来像是一个对象字面量。

Rule Details

This rule aims to flag any empty patterns in destructured objects and arrays, and as such, will report a problem whenever one is encountered.

此规则目的在于标记出在解构对象和数组中的任何的空模式,每当遇到一个这样的空模式,该规则就会报告一个问题。

Examples of incorrect code for this rule:

错误 代码示例:

/*eslint no-empty-pattern: "error"*/

var {} = foo;
var [] = foo;
var {a: {}} = foo;
var {a: []} = foo;
function foo({}) {}
function foo([]) {}
function foo({a: {}}) {}
function foo({a: []}) {}

Examples of correct code for this rule:

正确 代码示例:

/*eslint no-empty-pattern: "error"*/

var {a = {}} = foo;
var {a = []} = foo;
function foo({a = {}}) {}
function foo({a = []}) {}

Version

This rule was introduced in ESLint 1.7.0.

该规则在 ESLint 1.7.0 中被引入。

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