'use strict'; require('../common'); const RuleTester = require('../../tools/eslint').RuleTester; const rule = require('../../tools/eslint-rules/no-let-in-for-declaration'); const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 6 } }); const message = 'Use of `let` as the loop variable in a for-loop is ' + 'not recommended. Please use `var` instead.'; ruleTester.run('no-let-in-for-declaration', rule, { valid: [ 'let foo;', 'for (var foo = 1;;);', 'for (foo = 1;;);', 'for (;;);', 'for (const foo of bar);', 'for (var foo of bar);', 'for (const foo in bar);', 'for (var foo in bar);' ], invalid: [ { code: 'for (let foo = 1;;);', errors: [{ message }] }, { code: 'for (let foo in bar);', errors: [{ message }] }, { code: 'for (let foo of bar);', errors: [{ message }] } ] });