useArraySome

JavaScript (and super languages)

Note

This rule has been implemented but not released yet. It will be available in the next release.

Caution

This rule is part of the nursery group. This means that it is experimental and the behavior can change at any time.

Summary

• Diagnostic Category: lint/nursery/useArraySome
• This rule has an unsafe fix.
• The default severity of this rule is information.
• Sources:
  • Inspired from unicorn/prefer-array-some

How to configure

biome.json

{
  "linter": {
    "rules": {
      "nursery": {
        "useArraySome": "error"
      }
    }
  }
}

Description

Prefer Array.prototype.some() over verbose existence checks.

Examples

Invalid

array.filter(predicate).length > 0;

code-block.js:1:1 lint/nursery/useArraySome  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Prefer .some() over filter(…).length comparison.
  
  > 1 │ array.filter(predicate).length > 0;
      │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Using .filter() followed by a length check iterates the entire array unnecessarily. .some() stops at the first match.
  
  ℹ Use .some() when you only need to know if any element matches.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
  
  ℹ Unsafe fix: Use .some() instead.
  
    1   │ - array.filter(predicate).length·>·0;
      1 │ + array.some(predicate);
    2 2 │   
  

array.findIndex(predicate) !== -1;

code-block.js:1:1 lint/nursery/useArraySome  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Prefer .some() over findIndex(…) !== -1.
  
  > 1 │ array.findIndex(predicate) !== -1;
      │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Use .some() when you only need to know if any element matches.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
  
  ℹ Unsafe fix: Use .some() instead.
  
    1   │ - array.findIndex(predicate)·!==·-1;
      1 │ + array.some(predicate);
    2 2 │   
  

if (array.find(predicate)) {}

code-block.js:1:5 lint/nursery/useArraySome ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Prefer .some() over find-family used as boolean.
  
  > 1 │ if (array.find(predicate)) {}
      │     ^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Use .some() when you only need to know if any element matches.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
  

array.find(predicate) != null;

code-block.js:1:1 lint/nursery/useArraySome ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Prefer .some() over find(…) existence comparison.
  
  > 1 │ array.find(predicate) != null;
      │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Use .some() when you only need to know if any element matches.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
  

array.findLastIndex(predicate) !== -1;

code-block.js:1:1 lint/nursery/useArraySome  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Prefer .some() over findLastIndex(…) !== -1.
  
  > 1 │ array.findLastIndex(predicate) !== -1;
      │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Use .some() when you only need to know if any element matches.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
  
  ℹ Unsafe fix: Use .some() instead.
  
    1   │ - array.findLastIndex(predicate)·!==·-1;
      1 │ + array.some(predicate);
    2 2 │   
  

if (array.findLast(predicate)) {}

code-block.js:1:5 lint/nursery/useArraySome ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Prefer .some() over find-family used as boolean.
  
  > 1 │ if (array.findLast(predicate)) {}
      │     ^^^^^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Use .some() when you only need to know if any element matches.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
  

Valid

array.some(predicate);

Related links

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• Source Code
• Test Cases