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# Array Formatting
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Rules that control the formatting and styling of JavaScript arrays, including bracket spacing, newlines, and element positioning.
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## array-bracket-newline
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Enforces linebreaks after opening and before closing array brackets.
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```javascript { .api }
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const arrayBracketNewline: Rule.RuleModule;
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// Rule options
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type ArrayBracketNewlineOptions = 
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  | 'always' 
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  | 'never' 
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  | 'consistent'
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  | {
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      multiline?: boolean;
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      minItems?: number | null;
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    };
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```
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**Usage Examples:**
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```javascript
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// ✓ Good with "always"
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const items = [
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  'apple',
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  'banana'
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];
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// ✓ Good with "never"
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const items = ['apple', 'banana'];
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// ✓ Good with { multiline: true }
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const items = ['apple', 'banana']; // single line ok
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const items = [
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  'apple',
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  'banana'
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]; // multiline requires brackets on new lines
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```
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**Configuration:**
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```javascript
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rules: {
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  '@stylistic/js/array-bracket-newline': ['error', 'consistent']
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}
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```
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## array-bracket-spacing
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Enforces consistent spacing inside array brackets.
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```javascript { .api }
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const arrayBracketSpacing: Rule.RuleModule;
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// Rule options
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type ArrayBracketSpacingOptions = 
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  | 'always'
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  | 'never'
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  | ['always' | 'never', {
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      singleValue?: boolean;
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      objectsInArrays?: boolean;
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      arraysInArrays?: boolean;
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    }];
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```
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**Usage Examples:**
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```javascript
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// ✓ Good with "never" (default)
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const items = ['apple', 'banana'];
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// ✓ Good with "always"
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const items = [ 'apple', 'banana' ];
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// ✓ Good with custom options
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const items = ['apple', 'banana']; // singleValue: false
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const nested = [[ 'nested' ]]; // arraysInArrays: false
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```
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**Configuration:**
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```javascript
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rules: {
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  '@stylistic/js/array-bracket-spacing': ['error', 'never']
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}
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```
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## array-element-newline
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Enforces line breaks after each array element.
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```javascript { .api }
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const arrayElementNewline: Rule.RuleModule;
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// Rule options
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type ArrayElementNewlineOptions =
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  | 'always'
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  | 'never'
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  | 'consistent'
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  | {
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      multiline?: boolean;
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      minItems?: number | null;
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    };
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```
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**Usage Examples:**
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```javascript
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// ✓ Good with "always"
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const items = [
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  'apple',
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  'banana',
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  'cherry'
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];
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// ✓ Good with "never"
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const items = ['apple', 'banana', 'cherry'];
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// ✓ Good with { minItems: 3 }
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const small = ['a', 'b']; // under threshold, no newlines required
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const large = [
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  'apple',
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  'banana', 
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  'cherry'
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]; // meets threshold, newlines required
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```
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**Configuration:**
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```javascript
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rules: {
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  '@stylistic/js/array-element-newline': ['error', { minItems: 3 }]
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}
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```
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## Common Array Formatting Combinations
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Here are some popular combinations for array formatting:
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### Compact Arrays
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```javascript
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rules: {
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  '@stylistic/js/array-bracket-spacing': ['error', 'never'],
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  '@stylistic/js/array-bracket-newline': ['error', 'never'],
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  '@stylistic/js/array-element-newline': ['error', 'never']
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}
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// Result:
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const items = ['apple', 'banana', 'cherry'];
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```
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### Multiline Arrays
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```javascript
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rules: {
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  '@stylistic/js/array-bracket-spacing': ['error', 'never'],
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  '@stylistic/js/array-bracket-newline': ['error', { multiline: true }],
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  '@stylistic/js/array-element-newline': ['error', { minItems: 3 }]
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}
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// Result:
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const short = ['a', 'b'];
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const long = [
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  'apple',
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  'banana',
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  'cherry'
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];
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```
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## Type Definitions
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```typescript { .api }
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// Complete type definitions for array rules
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interface ArrayBracketNewlineRule {
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  meta: {
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    type: 'layout';
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    docs: { description: string };
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    fixable: 'whitespace';
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    schema: JSONSchema4[];
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  };
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  create(context: Rule.RuleContext): Rule.RuleListener;
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}
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interface ArrayFormattingRules {
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  'array-bracket-newline': ArrayBracketNewlineRule;
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  'array-bracket-spacing': Rule.RuleModule;
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  'array-element-newline': Rule.RuleModule;
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}
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```