node/tools/eslint/lib/rules/prefer-reflect.js

/**
 * @fileoverview Rule to suggest using "Reflect" api over Function/Object methods
 * @author Keith Cirkel <http://keithcirkel.co.uk>
 * @copyright 2015 Keith Cirkel. All rights reserved.
 */
"use strict";

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

module.exports = function(context) {
    var existingNames = {
        "apply": "Function.prototype.apply",
        "call": "Function.prototype.call",
        "defineProperty": "Object.defineProperty",
        "getOwnPropertyDescriptor": "Object.getOwnPropertyDescriptor",
        "getPrototypeOf": "Object.getPrototypeOf",
        "setPrototypeOf": "Object.setPrototypeOf",
        "isExtensible": "Object.isExtensible",
        "getOwnPropertyNames": "Object.getOwnPropertyNames",
        "preventExtensions": "Object.preventExtensions"
    };

    var reflectSubsitutes = {
        "apply": "Reflect.apply",
        "call": "Reflect.apply",
        "defineProperty": "Reflect.defineProperty",
        "getOwnPropertyDescriptor": "Reflect.getOwnPropertyDescriptor",
        "getPrototypeOf": "Reflect.getPrototypeOf",
        "setPrototypeOf": "Reflect.setPrototypeOf",
        "isExtensible": "Reflect.isExtensible",
        "getOwnPropertyNames": "Reflect.getOwnPropertyNames",
        "preventExtensions": "Reflect.preventExtensions"
    };

    var exceptions = (context.options[0] || {}).exceptions || [];

    /**
     * Reports the Reflect violation based on the `existing` and `substitute`
     * @param {Object} node The node that violates the rule.
     * @param {string} existing The existing method name that has been used.
     * @param {string} substitute The Reflect substitute that should be used.
     * @returns {void}
     */
    function report(node, existing, substitute) {
        context.report(node, "Avoid using {{existing}}, instead use {{substitute}}", {
            existing: existing,
            substitute: substitute
        });
    }

    return {
        "CallExpression": function(node) {
            var methodName = (node.callee.property || {}).name;
            var isReflectCall = (node.callee.object || {}).name === "Reflect";
            var hasReflectSubsitute = reflectSubsitutes.hasOwnProperty(methodName);
            var userConfiguredException = exceptions.indexOf(methodName) !== -1;
            if (hasReflectSubsitute && !isReflectCall && !userConfiguredException) {
                report(node, existingNames[methodName], reflectSubsitutes[methodName]);
            }
        },
        "UnaryExpression": function(node) {
            var isDeleteOperator = node.operator === "delete";
            var targetsIdentifier = node.argument.type === "Identifier";
            var userConfiguredException = exceptions.indexOf("delete") !== -1;
            if (isDeleteOperator && !targetsIdentifier && !userConfiguredException) {
                report(node, "the delete keyword", "Reflect.deleteProperty");
            }
        }
    };

};

module.exports.schema = [
    {
        "type": "object",
        "properties": {
            "exceptions": {
                "type": "array",
                "items": {
                    "enum": [
                        "apply",
                        "call",
                        "delete",
                        "defineProperty",
                        "getOwnPropertyDescriptor",
                        "getPrototypeOf",
                        "setPrototypeOf",
                        "isExtensible",
                        "getOwnPropertyNames",
                        "preventExtensions"
                    ]
                },
                "uniqueItems": true
            }
        },
        "additionalProperties": false
    }
];