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build: add ESLint rule to disallow new Array(...)
PR-URL: #5493 Closes: stdlib-js/metr-issue-tracker#28 Co-authored-by: Athan Reines <kgryte@gmail.com> Reviewed-by: Athan Reines <kgryte@gmail.com>
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‎etc/eslint/rules/stdlib.js

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@@ -4310,6 +4310,38 @@ rules[ 'stdlib/no-dynamic-exports' ] = 'error';
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*/
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rules[ 'stdlib/no-nested-require' ] = 'error';
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/**
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* Disallow the use of the `new Array()` constructor.
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*
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* @name no-new-array
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* @memberof rules
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* @type {string}
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* @default 'error'
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*
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* @example
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* // Bad...
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* var arr = new Array( 5 );
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* var i;
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* for ( i = 0; i < 5; i++ ) {
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* arr[ i ] = i;
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* }
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*
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* console.log( arr );
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* // => [ 0, 1, 2, 3, 4 ]
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*
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* @example
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* // Good...
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* var arr = [];
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* var i;
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* for ( i = 0; i < 5; i++ ) {
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* arr.push( i );
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* }
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*
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* console.log( arr );
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* // => [ 0, 1, 2, 3, 4 ]
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*/
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rules[ 'stdlib/no-new-array' ] = 'error';
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/**
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* Never allow a variable to be declared multiple times within the same scope or for built-in globals to be redeclared.
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*

‎lib/node_modules/@stdlib/_tools/eslint/rules/lib/index.js

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@@ -909,6 +909,15 @@ setReadOnly( rules, 'no-multiple-empty-lines', require( '@stdlib/_tools/eslint/r
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*/
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setReadOnly( rules, 'no-nested-require', require( '@stdlib/_tools/eslint/rules/no-nested-require' ) );
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/**
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* @name no-new-array
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* @memberof rules
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* @readonly
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* @type {Function}
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* @see {@link module:@stdlib/_tools/eslint/rules/no-new-array}
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*/
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setReadOnly( rules, 'no-new-array', require( '@stdlib/_tools/eslint/rules/no-new-array' ) );
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/**
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* @name no-redeclare
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* @memberof rules

‎lib/node_modules/@stdlib/_tools/eslint/rules/no-new-array/README.md

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<!--
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@license Apache-2.0
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Copyright (c) 2025 The Stdlib Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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-->
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# no-new-array
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> [ESLint rule][eslint-rules] disallowing the use of the `new Array()` constructor.
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<section class="intro">
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</section>
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<!-- /.intro -->
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<section class="usage">
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## Usage
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```javascript
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var rule = require( '@stdlib/_tools/eslint/rules/no-new-array' );
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```
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#### rule
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[ESLint rule][eslint-rules] disallowing the use of the `new Array()` constructor.
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**Bad**:
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<!-- eslint-disable stdlib/no-new-array -->
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```javascript
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var arr = new Array( 5 );
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var i;
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for ( i = 0; i < 5; i++ ) {
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arr[ i ] = i;
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}
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console.log( arr );
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// => [ 0, 1, 2, 3, 4 ]
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```
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**Good**:
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```javascript
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var arr = [];
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var i;
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for ( i = 0; i < 5; i++ ) {
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arr.push( i );
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}
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console.log( arr );
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// => [ 0, 1, 2, 3, 4 ]
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```
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</section>
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<!-- /.usage -->
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<section class="examples">
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## Examples
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```javascript
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var Linter = require( 'eslint' ).Linter;
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var rule = require( '@stdlib/_tools/eslint/rules/no-new-array' );
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var linter = new Linter();
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var code = 'var arr = new Array( 5 );';
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linter.defineRule( 'no-new-array', rule );
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var result = linter.verify( code, {
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'rules': {
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'no-new-array': 'error'
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}
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});
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/* returns
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[
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{
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'ruleId': 'no-new-array',
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'severity': 2,
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'message': 'Using the `new Array()` constructor is not allowed; use an array literal with push instead.',
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'line': 1,
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'column': 14,
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'nodeType': 'CallExpression',
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'source': 'var arr = new Array( 5 );',
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'endLine': 1,
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'endColumn': 25
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}
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]
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*/
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```
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<!-- /.examples -->
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<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
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<section class="related">
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</section>
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<!-- /.related -->
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<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
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<section class="links">
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[eslint-rules]: https://eslint.org/docs/developer-guide/working-with-rules
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</section>
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<!-- /.links -->

‎lib/node_modules/@stdlib/_tools/eslint/rules/no-new-array/examples/index.js

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/**
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* @license Apache-2.0
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*
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* Copyright (c) 2025 The Stdlib Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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'use strict';
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var Linter = require( 'eslint' ).Linter;
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var rule = require( './../lib' );
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var linter = new Linter();
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var code = 'var arr = new Array( 5 );';
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linter.defineRule( 'no-new-array', rule );
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var result = linter.verify( code, {
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'rules': {
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'no-new-array': 'error'
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}
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});
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console.log( result );
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/* =>
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[
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{
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'ruleId': 'no-new-array',
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'severity': 2,
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'message': 'Using the `new Array()` constructor is not allowed; use an array literal with push instead.',
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'line': 1,
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'column': 14,
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'nodeType': 'CallExpression',
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'source': 'var arr = new Array( 5 );',
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'endLine': 1,
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'endColumn': 25
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}
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]
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*/

‎lib/node_modules/@stdlib/_tools/eslint/rules/no-new-array/lib/index.js

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/**
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* @license Apache-2.0
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*
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* Copyright (c) 2025 The Stdlib Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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'use strict';
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/**
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* ESLint rule disallowing the use of the `new Array()` constructor.
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*
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* @module @stdlib/_tools/eslint/rules/no-new-array
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*
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* @example
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* var rule = require( '@stdlib/_tools/eslint/rules/no-new-array' );
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*
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* console.log( rule );
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*/
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// MODULES //
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var main = require( './main.js' );
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// EXPORTS //
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module.exports = main;

‎lib/node_modules/@stdlib/_tools/eslint/rules/no-new-array/lib/main.js

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/**
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* @license Apache-2.0
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*
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* Copyright (c) 2025 The Stdlib Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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'use strict';
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// VARIABLES //
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var rule;
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// FUNCTIONS //
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/**
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* Rule for disallowing the use of the `new Array()` constructor.
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*
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* @param {Object} context - ESLint context
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* @returns {Object} validators
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*/
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function main( context ) {
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/**
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* Reports the error message.
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*
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* @private
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* @param {ASTNode} node - node to report
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*/
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function report( node ) {
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context.report({
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'node': node,
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'message': 'Using the `new Array()` constructor is not allowed; use an array literal with push instead.'
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});
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}
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/**
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* Checks whether a node is a `new Array()` expression.
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*
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* @private
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* @param {ASTNode} node - node to examine
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*/
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function validate( node ) {
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if (
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node.callee &&
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node.callee.name === 'Array'
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) {
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report( node );
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}
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}
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return {
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'NewExpression': validate
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};
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}
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// MAIN //
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rule = {
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'meta': {
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'type': 'suggestion',
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'docs': {
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'description': 'disallow the use of the `new Array()` constructor'
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},
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'schema': []
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},
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'create': main
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};
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// EXPORTS //
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module.exports = rule;

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