Gulpfile.js

var gulp        = require('gulp');
var babel       = require('gulp-babel');
var del         = require('del');
var path        = require('path');
var spawn       = require('./utils/spawn');


var PACKAGE_PARENT_DIR  = path.join(__dirname, '../');
var PACKAGE_SEARCH_PATH = (process.env.NODE_PATH ? process.env.NODE_PATH + path.delimiter : '') + PACKAGE_PARENT_DIR;


function clean () {
    return del('lib');
}

function lint () {
    var eslint = require('gulp-eslint');

    return gulp
        .src([
            'src/**/*.js',
            'test/**/*.js',
            'Gulpfile.js'
        ])
        .pipe(eslint())
        .pipe(eslint.format())
        .pipe(eslint.failAfterError());
}

function build () {
    return gulp
        .src('src/**/*.js')
        .pipe(babel())
        .pipe(gulp.dest('lib'));
}

function testMocha () {
    if (!process.env.SAUCE_USERNAME || !process.env.SAUCE_ACCESS_KEY)
        throw new Error('Specify your credentials by using the SAUCE_USERNAME and SAUCE_ACCESS_KEY environment variables to authenticate to SauceLabs.');

    var mochaCmd = path.join(__dirname, 'node_modules/.bin/mocha');

    var mochaOpts = [
        '--ui', 'bdd',
        '--reporter', 'spec',
        '--timeout', typeof v8debug === 'undefined' ? 2000 : Infinity,
        'test/mocha/**/*.js'
    ];

    // NOTE: we must add the parent of plugin directory to NODE_PATH, otherwise testcafe will not be able
    // to find the plugin. So this function starts mocha with proper NODE_PATH.
    return spawn(mochaCmd, mochaOpts, { NODE_PATH: PACKAGE_SEARCH_PATH });
}

function testTestcafe () {
    if (!process.env.SAUCE_USERNAME || !process.env.SAUCE_ACCESS_KEY)
        throw new Error('Specify your credentials by using the SAUCE_USERNAME and SAUCE_ACCESS_KEY environment variables to authenticate to SauceLabs.');

    var testCafeCmd = path.join(__dirname, 'node_modules/.bin/testcafe');

    var testCafeOpts = [
        'saucelabs:chrome',
        'test/testcafe/**/*.js',
        '-s', '.screenshots'
    ];

    // NOTE: we must add the parent of plugin directory to NODE_PATH, otherwise testcafe will not be able
    // to find the plugin. So this function starts testcafe with proper NODE_PATH.
    return spawn(testCafeCmd, testCafeOpts, { NODE_PATH: PACKAGE_SEARCH_PATH });
}

exports.clean       = clean;
exports.lint        = lint;
exports.build       = gulp.parallel(lint, gulp.series(clean, build));
exports.testMocha   = gulp.series(exports.build, testMocha);
exports.testNoBuild = gulp.series(testMocha, testTestcafe);
exports.test        = gulp.series(exports.build, exports.testNoBuild);