eslint-plugin-unicorn/rules/utils/is-shadowed.js

More than 100 powerful ESLint rules

/**
Finds the eslint-scope reference in the given scope.

@param {Object} scope The scope to search.
@param {ASTNode} node The identifier node.
@returns {Reference|undefined} Returns the found reference or null if none were found.
*/
function findReference(scope, node) {
	const references = scope.references
		.filter(reference => reference.identifier === node);

	if (references.length === 1) {
		return references[0];
	}
}

/**
Checks if the given identifier node is shadowed in the given scope.

@param {Object} scope The current scope.
@param {string} node The identifier node to check
@returns {boolean} Whether or not the name is shadowed.
*/
export default function isShadowed(scope, node) {
	const reference = findReference(scope, node);

	return (
		Boolean(reference?.resolved)
		&& reference.resolved.defs.length > 0
	);
}