TypeScript linter

lint.js

var configuration = {
    rules: {
        'variable-name': true,
        'comment-format': [true, 'check-space'],
        'curly': true,
        'eofline': true,
        'forin': true,
        'indent': [true, 'spaces'],
        'jsdoc-format': true,
        'no-switch-case-fall-through': true,
        'no-trailing-whitespace': true,
        'no-unreachable': true,
        'no-unused-variable': true,
        'no-var-keyword': true,
        'quotemark': [true, 'single', 'avoid-escape'],
        'semicolon': true,
        'switch-default': true,
        'trailing-comma': [true],
        'triple-equals': true,
        'typedef': [true],
        'typedef-whitespace': [true],
        'variable-name': [false],
        'whitespace': [
            true,
            'check-branch',
            'check-decl',
            'check-operator',
            'check-separator',
            'check-type'
        ]
    }
};

var options = {
    formatter: 'json',
    configuration: configuration
};

var Linter = require('tslint');
var chalk = require('chalk');
var fs = require('fs');
var path = require('path');

function checkDirectory (directory) {
    var errors = 0;
    fs.readdirSync(directory).forEach(function (file) {
        file = path.join(directory, file);
        if (fs.lstatSync(file).isDirectory()) {
            errors += checkDirectory(file);
        } else {
            var extension = path.extname(file);
            if (extension === '.ts' || extension == '.tsx') {
                errors += lint(file);
            }
        }
    });
    return errors;
}

function lint (file) {
    var linter = new Linter(file, fs.readFileSync(file).toString('utf8'), options);
    var results = linter.lint();
    var output = JSON.parse(results.output);
    if (output.length === 0) {
        console.log(chalk.bold.green(' \u2714 ' + chalk.gray(file)));
        return 0;
    }
    console.log(chalk.bold.red(' \u2718 ' + chalk.gray(file + ' ' + chalk.red(output.length + ' Errors'))));
    output.forEach(function (error) {
        console.log(chalk.gray('  ' + parsePosition(error.startPosition) + ' - ' + parsePosition(error.endPosition) + ' ' + error.failure));
    });
    return output.length;
}

function parsePosition (position) {
    return position.line + ':' + position.character;
}

var errors = checkDirectory('./');
if (errors !== 0) {
    console.log(chalk.bold(errors + ' errors found.'));
    process.exit(-1);
}