2025-04-19 23:12:19 -04:00

85 lines
2.0 KiB
JavaScript

/**
* @fileoverview Rule to flag references to undeclared variables.
* @author Mark Macdonald
*/
'use strict';
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
/**
* Checks if the given node is the argument of a typeof operator.
* @param {ASTNode} node The AST node being checked.
* @returns {boolean} Whether or not the node is the argument of a typeof operator.
*/
function hasTypeOfOperator(node) {
const parent = node.parent;
return parent.type === 'UnaryExpression' && parent.operator === 'typeof';
}
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../types').Rule.RuleModule} */
module.exports = {
meta: {
type: 'problem',
defaultOptions: [
{
typeof: false,
},
],
docs: {
description:
'Disallow the use of undeclared variables unless mentioned in `/*global */` comments',
recommended: true,
url: 'https://eslint.org/docs/latest/rules/no-undef',
},
schema: [
{
type: 'object',
properties: {
typeof: {
type: 'boolean',
},
},
additionalProperties: false,
},
],
messages: {
undef: "'{{name}}' is not defined.",
},
},
create(context) {
const [{ typeof: considerTypeOf }] = context.options;
const sourceCode = context.sourceCode;
return {
'Program:exit'(node) {
const globalScope = sourceCode.getScope(node);
globalScope.through.forEach((ref) => {
const identifier = ref.identifier;
if (!considerTypeOf && hasTypeOfOperator(identifier)) {
return;
}
context.report({
node: identifier,
messageId: 'undef',
data: identifier,
});
});
},
};
},
};