noEmptyPattern (JavaScript)

Language JavaScript (and super languages)

Summary

Rule available since: v1.0.0
Diagnostic Category: lint/correctness/noEmptyPattern
This rule is recommended, meaning it is enabled by default.
This rule doesn’t have a fix.
The default severity of this rule is error.
Sources:
- Same as no-empty-pattern
- Same as vue/no-empty-pattern

How to configure

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{
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  "linter": {
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    "rules": {
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      "correctness": {
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        "noEmptyPattern": "error"
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      }
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    }
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  }
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}

Description

Disallow empty object and array destructuring patterns.

Destructuring extracts values into new variables. An empty pattern extracts nothing and creates no variables, which is usually a mistake.

Examples

Invalid

1
var {} = foo;

code-block.js:1:5 lint/correctness/noEmptyPattern ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Unexpected empty object pattern.
  
  > 1 │ var {} = foo;
      │     ^^
    2 │ 
  
  ℹ An empty pattern does not create any variables, but it can still throw an error for an invalid value.
  
  ℹ Add the names you want to extract, or remove the pattern.

1
var {a: {}} = foo;

code-block.js:1:9 lint/correctness/noEmptyPattern ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Unexpected empty object pattern.
  
  > 1 │ var {a: {}} = foo;
      │         ^^
    2 │ 
  
  ℹ An empty pattern does not create any variables, but it can still throw an error for an invalid value.
  
  ℹ Add the names you want to extract, or remove the pattern.

1
function foo({}) {}

code-block.js:1:14 lint/correctness/noEmptyPattern ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Unexpected empty object pattern.
  
  > 1 │ function foo({}) {}
      │              ^^
    2 │ 
  
  ℹ An empty pattern does not create any variables, but it can still throw an error for an invalid value.
  
  ℹ Add the names you want to extract, or remove the pattern.

Valid

The following patterns are valid because they create at least one variable.

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