eslint/lib/rules/no-multi-str.js

/**
 * @fileoverview Rule to flag when using multiline strings
 * @author Ilya Volodin
 */

"use strict";

//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------

const astUtils = require("./utils/ast-utils");

//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------

module.exports = {
    meta: {
        type: "suggestion",

        docs: {
            description: "disallow multiline strings",
            category: "Best Practices",
            recommended: false,
            url: "https://eslint.org/docs/rules/no-multi-str"
        },

        schema: [],

        messages: {
            multilineString: "Multiline support is limited to browsers supporting ES5 only."
        }
    },

    create(context) {

        /**
         * Determines if a given node is part of JSX syntax.
         * @param {ASTNode} node The node to check.
         * @returns {boolean} True if the node is a JSX node, false if not.
         * @private
         */
        function isJSXElement(node) {
            return node.type.indexOf("JSX") === 0;
        }

        //--------------------------------------------------------------------------
        // Public API
        //--------------------------------------------------------------------------

        return {

            Literal(node) {
                if (astUtils.LINEBREAK_MATCHER.test(node.raw) && !isJSXElement(node.parent)) {
                    context.report({
                        node,
                        messageId: "multilineString"
                    });
                }
            }
        };

    }
};