codtracker-js/node_modules/eslint/lib/rules/no-case-declarations.js
2025-04-19 23:12:19 -04:00

75 lines
2.0 KiB
JavaScript

/**
* @fileoverview Rule to flag use of an lexical declarations inside a case clause
* @author Erik Arvidsson
*/
'use strict';
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../types').Rule.RuleModule} */
module.exports = {
meta: {
type: 'suggestion',
docs: {
description: 'Disallow lexical declarations in case clauses',
recommended: true,
url: 'https://eslint.org/docs/latest/rules/no-case-declarations',
},
hasSuggestions: true,
schema: [],
messages: {
addBrackets: 'Add {} brackets around the case block.',
unexpected: 'Unexpected lexical declaration in case block.',
},
},
create(context) {
/**
* Checks whether or not a node is a lexical declaration.
* @param {ASTNode} node A direct child statement of a switch case.
* @returns {boolean} Whether or not the node is a lexical declaration.
*/
function isLexicalDeclaration(node) {
switch (node.type) {
case 'FunctionDeclaration':
case 'ClassDeclaration':
return true;
case 'VariableDeclaration':
return node.kind !== 'var';
default:
return false;
}
}
return {
SwitchCase(node) {
for (let i = 0; i < node.consequent.length; i++) {
const statement = node.consequent[i];
if (isLexicalDeclaration(statement)) {
context.report({
node: statement,
messageId: 'unexpected',
suggest: [
{
messageId: 'addBrackets',
fix: (fixer) => [
fixer.insertTextBefore(node.consequent[0], '{ '),
fixer.insertTextAfter(node.consequent.at(-1), ' }'),
],
},
],
});
}
}
},
};
},
};