disallow-var.js

/**
 * Disallows declaring variables with `var`.
 *
 * Types: `Boolean`
 *
 * Values: `true`
 *
 * Version: `ES6`
 *
 * #### Example
 *
 * ```js
 * "disallowVar": true
 * ```
 *
 * ##### Valid
 *
 * ```js
 * let foo;
 * const bar;
 * ```
 *
 * ##### Invalid
 *
 * ```js
 * var baz;
 * ```
 */

var assert = require('assert');

module.exports = function() { };

module.exports.prototype = {
    configure: function(option) {
        assert(option === true, this.getOptionName() + ' requires a true value');
    },

    getOptionName: function() {
        return 'disallowVar';
    },

    check: function(file, errors) {
        file.iterateNodesByType('VariableDeclaration', function(node) {
            for (var i = 0; i < node.declarations.length; i++) {
                var thisDeclaration = node.declarations[i];

                if (thisDeclaration.parentElement.kind === 'var') {
                    errors.add('Variable declarations should use `let` or `const` not `var`', node);
                }
            }
        });
    }
};