node/tools/eslint-rules/no-array-destructuring.js
Antoine du Hamel 26288ff25e tools: add ESLint rule no-array-destructuring
Iterating over arrays should be avoided because it relies on
user-mutable global methods (`Array.prototype[Symbol.iterator]`
and `%ArrayIteratorPrototype%.next`), we should instead use
other alternatives. This commit adds a rule that disallow
array destructuring syntax in favor of object destructuring syntax.
Note that you can ignore this rule if you are using
the array destructuring syntax over a safe iterable, or
actually want to iterate over a user-provided object.

PR-URL: https://github.com/nodejs/node/pull/36818
Reviewed-By: Rich Trott <rtrott@gmail.com>
2021-03-03 19:53:28 +01:00

84 lines
2.7 KiB
JavaScript

/**
* @fileoverview Iterating over arrays should be avoided because it relies on
* user-mutable global methods (`Array.prototype[Symbol.iterator]`
* and `%ArrayIteratorPrototype%.next`), we should instead use
* other alternatives. This file defines a rule that disallow
* array destructuring syntax in favor of object destructuring
* syntax. Note that you can ignore this rule if you are using
* the array destructuring syntax over a safe iterable, or
* actually want to iterate over a user-provided object.
* @author aduh95 <duhamelantoine1995@gmail.com>
*/
'use strict';
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
const USE_OBJ_DESTRUCTURING =
'Use object destructuring instead of array destructuring.';
const USE_ARRAY_METHODS =
'Use primordials.ArrayPrototypeSlice to avoid unsafe array iteration.';
const findComma = (sourceCode, elements, i, start) => {
if (i === 0)
return sourceCode.getTokenAfter(sourceCode.getTokenByRangeStart(start));
let element;
const originalIndex = i;
while (i && !element) {
element = elements[--i];
}
let token = sourceCode.getTokenAfter(
element ?? sourceCode.getTokenByRangeStart(start)
);
for (; i < originalIndex; i++) {
token = sourceCode.getTokenAfter(token);
}
return token;
};
const createFix = (fixer, sourceCode, { range: [start, end], elements }) => [
fixer.replaceTextRange([start, start + 1], '{'),
fixer.replaceTextRange([end - 1, end], '}'),
...elements.map((node, i) =>
(node === null ?
fixer.remove(findComma(sourceCode, elements, i, start)) :
fixer.insertTextBefore(node, i + ':'))
),
];
const arrayPatternContainsRestOperator = ({ elements }) =>
elements?.find((node) => node?.type === 'RestElement');
module.exports = {
meta: {
type: 'suggestion',
fixable: 'code',
schema: [],
},
create(context) {
const sourceCode = context.getSourceCode();
return {
ArrayPattern(node) {
const hasRest = arrayPatternContainsRestOperator(node);
context.report({
message: hasRest ? USE_ARRAY_METHODS : USE_OBJ_DESTRUCTURING,
node: hasRest || node,
fix: hasRest ?
undefined :
(fixer) => [
...(node.parent.type === 'AssignmentExpression' ?
[
fixer.insertTextBefore(node.parent, '('),
fixer.insertTextAfter(node.parent, ')'),
] :
[]),
...createFix(fixer, sourceCode, node),
],
});
},
};
},
};