eslint/no-empty-pattern Correctness

✅ This rule is turned on by default.

What it does

Disallow empty destructuring patterns

Why is this bad?

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:

// 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:

// 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:

// 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.

Examples of incorrect code for this rule:

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:

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

How to use

To enable this rule in the CLI or using the config file, you can use:

CLI

oxlint --deny no-empty-pattern

Config (.oxlintrc.json)

{
  "rules": {
    "no-empty-pattern": "error"
  }
}

References

• Rule Source