/** * @fileoverview Disallow sparse arrays * @author Nicholas C. Zakas */ "use strict"; //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ module.exports = { meta: { docs: { description: "disallow sparse arrays", category: "Possible Errors", recommended: true }, schema: [] }, create(context) { //-------------------------------------------------------------------------- // Public //-------------------------------------------------------------------------- return { ArrayExpression(node) { const emptySpot = node.elements.indexOf(null) > -1; if (emptySpot) { context.report({ node, message: "Unexpected comma in middle of array." }); } } }; } };