/** * @fileoverview Enforce newlines between operands of ternary expressions * @author Kai Cataldo */ "use strict"; const astUtils = require("../util/ast-utils"); //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ module.exports = { meta: { docs: { description: "enforce newlines between operands of ternary expressions", category: "Stylistic Issues", recommended: false, url: "https://eslint.org/docs/rules/multiline-ternary" }, schema: [ { enum: ["always", "always-multiline", "never"] } ] }, create(context) { const option = context.options[0]; const multiline = option !== "never"; const allowSingleLine = option === "always-multiline"; //-------------------------------------------------------------------------- // Helpers //-------------------------------------------------------------------------- /** * Tests whether node is preceded by supplied tokens * @param {ASTNode} node - node to check * @param {ASTNode} parentNode - parent of node to report * @param {boolean} expected - whether newline was expected or not * @returns {void} * @private */ function reportError(node, parentNode, expected) { context.report({ node, message: "{{expected}} newline between {{typeOfError}} of ternary expression.", data: { expected: expected ? "Expected" : "Unexpected", typeOfError: node === parentNode.test ? "test and consequent" : "consequent and alternate" } }); } //-------------------------------------------------------------------------- // Public //-------------------------------------------------------------------------- return { ConditionalExpression(node) { const areTestAndConsequentOnSameLine = astUtils.isTokenOnSameLine(node.test, node.consequent); const areConsequentAndAlternateOnSameLine = astUtils.isTokenOnSameLine(node.consequent, node.alternate); if (!multiline) { if (!areTestAndConsequentOnSameLine) { reportError(node.test, node, false); } if (!areConsequentAndAlternateOnSameLine) { reportError(node.consequent, node, false); } } else { if (allowSingleLine && node.loc.start.line === node.loc.end.line) { return; } if (areTestAndConsequentOnSameLine) { reportError(node.test, node, true); } if (areConsequentAndAlternateOnSameLine) { reportError(node.consequent, node, true); } } } }; } };