no-label-var.js•2.42 kB
/**
* @fileoverview Rule to flag labels that are the same as an identifier
* @author Ian Christian Myers
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const astUtils = require("./utils/ast-utils");
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../shared/types').Rule} */
module.exports = {
meta: {
type: "suggestion",
docs: {
description: "Disallow labels that share a name with a variable",
recommended: false,
url: "https://eslint.org/docs/latest/rules/no-label-var"
},
schema: [],
messages: {
identifierClashWithLabel: "Found identifier with same name as label."
}
},
create(context) {
const sourceCode = context.sourceCode;
//--------------------------------------------------------------------------
// Helpers
//--------------------------------------------------------------------------
/**
* Check if the identifier is present inside current scope
* @param {Object} scope current scope
* @param {string} name To evaluate
* @returns {boolean} True if its present
* @private
*/
function findIdentifier(scope, name) {
return astUtils.getVariableByName(scope, name) !== null;
}
//--------------------------------------------------------------------------
// Public API
//--------------------------------------------------------------------------
return {
LabeledStatement(node) {
// Fetch the innermost scope.
const scope = sourceCode.getScope(node);
/*
* Recursively find the identifier walking up the scope, starting
* with the innermost scope.
*/
if (findIdentifier(scope, node.label.name)) {
context.report({
node,
messageId: "identifierClashWithLabel"
});
}
}
};
}
};