A sample gulpfile and package.json for wordpress themes

sample_gulpfile.js

var CONFIG = {

    PROJECT_URL: 'https://nib.local',

    SOURCE: {
        scripts: 'source/js/**/*.js',
        styles: 'source/scss/**/*.scss',
        images: 'source/images/*',
        php: '**/*.php'
    },

    ASSETS: {
        styles: 'assets/styles/',
        scripts: 'assets/js/',
        images: 'assets/images/',
        all: 'assets/'
    },

    JSHINT_CONFIG: {
        "node": true,
        "esversion": 6,
        "globals": {
            "document": true,
            "jQuery": true
        }
    },

    TRANSLATION: {
        "pot_filename": 'functions/translation/NIB-theme.pot',
        "original_language": 'en',
        "target_languages": [
            'es',
            'zh'
        ]
    },

    AUTOPREFIXER_CONFIG: {
        browsers: ['last 2 versions', '> 5%', 'Firefox ESR']
    }
};

var gulp = require('gulp'),
    chalk = require('chalk'),

    _ = require('lodash'),
    gettextParser = require("gettext-parser"),
    AWS = require('aws-sdk'),

    pa11y = require('pa11y');

plugin = require('gulp-load-plugins')();

// GULP FUNCTIONS
// JSHint, concat, and minify JavaScript
gulp.task('scripts', function () {

    return gulp.src(CONFIG.SOURCE.scripts, {since: gulp.lastRun('scripts')})

        .pipe(plugin.plumber({errorHandler: reportError}))

        .pipe(plugin.sourcemaps.init())
        .pipe(plugin.babel({
            presets: ["@babel/preset-env"],
            compact: true,
            ignore: []
        }))

        // Only lint modified files
        .pipe(plugin.cached('scripts'))
        .pipe(plugin.jshint(CONFIG.JSHINT_CONFIG))
        .pipe(plugin.jshint.reporter('jshint-stylish'))
        .pipe(plugin.remember('scripts'))
        .pipe(plugin.concat('scripts.js'))
        .pipe(plugin.uglify())
        .pipe(plugin.sourcemaps.write('.')) // Creates sourcemap for minified JS
        .pipe(gulp.dest(CONFIG.ASSETS.scripts))
});


// Compile Sass, Autoprefix and minify
gulp.task('styles', function () {
    return gulp.src(CONFIG.SOURCE.styles)

        .pipe(plugin.plumber({errorHandler: reportError}))

        .pipe(plugin.sourcemaps.init())
        .pipe(plugin.sass())
        .pipe(plugin.autoprefixer({
            browsers: CONFIG.AUTOPREFIXER_CONFIG.browsers,
            cascade: false
        }))
        .pipe(plugin.cssnano())
        .pipe(plugin.sourcemaps.write('.'))
        .pipe(gulp.dest(CONFIG.ASSETS.styles));

});


// Optimize images, move into assets directory
gulp.task('images', function () {
    return gulp.src(CONFIG.SOURCE.images)
        .pipe(plugin.plumber({errorHandler: reportError}))
        .pipe(plugin.imagemin([], {
            verbose: true
        }))
        .pipe(gulp.dest(CONFIG.ASSETS.images))
});

// Automatically update the translation file
gulp.task('translate', function () {
    return gulp.src(CONFIG.SOURCE.php)
        .pipe(plugin.wpPot({
            domain: 'materiell-themes',
            package: 'NIB-theme'
        }))
        .pipe(gulp.dest(CONFIG.TRANSLATION.pot_filename));
});

// Automatically prettify the PHP
gulp.task('translate', function () {
    return gulp.src(CONFIG.SOURCE.php)
        .pipe(plugin.wpPot({
            domain: 'materiell-themes',
            package: 'NIB-theme'
        }))
        .pipe(gulp.dest(CONFIG.TRANSLATION.pot_filename));
});

gulp.task('pa11y', (done) => {
        pa11y({
            url: CONFIG.PROJECT_URL,
            // failOnError: true, // fail the build on error
            showFailedOnly: false, // show errors only and override reporter
            reporter: 'console'
        }).then((result) => {

            const color_wt = chalk.whiteBright;
            const color_lo = chalk.red;
            const color_hi = chalk.redBright;

            console.log(chalk.green.bold(`PA11Y: Ran pa11y for ${result.documentTitle}`));
            console.log(chalk.green(`PA11Y: URL::  ${result.pageUrl}`));

            if (result.issues.length > 0) {

                console.log(chalk.redBright(`PA11Y: ISSUES FOUND`));
                result.issues.forEach((i, e) => {
                    console.log(color_wt(`Context: ${i.context}`));
                    console.log(color_hi(`Message: ${i.message}`));
                    console.log(color_lo(`Code: ${i.code}`));
                    console.log(color_lo(`Selector: ${i.selector}`));
                    console.log(chalk.blueBright(`************************************`));
                });
            } else {
                console.log(chalk.green.bold(`PA11Y: No Issues Detected`));
            }
            done();
        });
    }
);


// Watch files for changes (without Browser-Sync)
gulp.task('watch', function () {

    // Watch .scss files
    gulp.watch(CONFIG.SOURCE.styles, gulp.parallel('styles'));

    // Watch scripts files
    gulp.watch(CONFIG.SOURCE.scripts, gulp.parallel('scripts'));

    // Watch images files
    gulp.watch(CONFIG.SOURCE.images, gulp.parallel('images'));

    // Watch pho files for translation
    gulp.watch(CONFIG.SOURCE.images, gulp.parallel('translate'));

});

// Run styles, scripts, etc
gulp.task('default', gulp.parallel('styles', 'scripts', 'images'));

/**
 * Helpers:
 *
 */

// outputs the errors from plumber
function reportError (error) {
    console.log(chalk.red(error.message));
    this.emit('end');
};

/**
 * TODO: Create autotranslate method using AWS-Translate
 *
 * https://github.com/smhg/gettext-parser        creates mo files and parses (maybe both) po/pot files
 *
 */

// Automatically create translations
gulp.task('auto_translate', function (done) {
    const language_jobs = generateTranslation(CONFIG.TRANSLATION.pot_filename);
    language_jobs.then((values) => {
        console.log("values:");
        console.dir(values);
        console.log("auto_translate done");
        done()
    });
});

const generateTranslation = (pot_filename) => {

    /**
     * SETUP:
     */

    console.log(chalk.greenBright.bold("Started Translating Assets"));
    console.log(chalk.green.bold(`POT_FILE: ${pot_filename}`));

    process.env.AWS_PROFILE = "jreeve-mat-us-east-1";
    AWS.config.update({region: 'us-east-1'});
    const translate = new AWS.Translate();

    const input = require('fs').readFileSync(pot_filename);
    const po = gettextParser.po.parse(input);

    /**
     * PER LANGUAGE:
     */

    let language_jobs = [];

    CONFIG.TRANSLATION.target_languages.forEach((lang_code) => {

        console.log("translating:  " + lang_code);
        // console.log("BEFORE:");
        // console.dir(po, { depth: null });

        /***
         * Get a bunch of translated strings
         */

        let translation_jobs = [];

        // first by context:
        _.each(po.translations, (translation_objects, context_key) => {

            _.each(translation_objects, (translation_string, translation_key) => {

                const params = {
                    SourceLanguageCode: CONFIG.TRANSLATION.original_language,
                    TargetLanguageCode: lang_code,
                    Text: translation_string.msgid,
                    MyParam: "SHAZAM"
                };

                if ("" === translation_string.msgid) {
                    // console.log("NO STRING");
                } else {

                    const translation_promise =
                        translate.translateText(params, (err, data) => {
                            // console.log(chalk.white.bold("msgid: ") + chalk.white(translation_string.msgid));
                            if (err) console.log(err, err.stack); // an error occurred
                            else {
                                // successful response
                                // console.log(data);
                                translation_string.msgstr = data.TranslatedText;
                                translation_objects[translation_key] = translation_string;
                            }
                            // console.log("()()()()()()(");
                            // console.dir(translation_objects);
                            // console.log("()()()()()()(");
                        }).promise();

                    translation_jobs.push(translation_promise);
                }
            });
        });

        // console.log(translation_jobs);
        language_jobs.push(
            Promise.all(translation_jobs)
        );

        /***
         * When they are done, write them out:
         */

        // Save .po and .mo

        // var output = gettextParser.po.compile(data);
        // require('fs').writeFileSync(output);
        //
        // var output = gettextParser.mo.compile(data);
        // require('fs').writeFileSync(output);

        // _.each(po.translations, (translation_objects, context_key) => {
        //
        //
        //     data.translations[context_key] = get_translation_for_context(lang_code, translation_objects);
        // });


    });
console.dir(language_jobs);
    return Promise.all(language_jobs);

};

function get_translation_for_context(lang_code, translation_objects) {

    const translate = new AWS.Translate();

    _.each(translation_objects, (el, i) => {

        const params = {
            SourceLanguageCode: CONFIG.TRANSLATION.original_language,
            TargetLanguageCode: lang_code,
            Text: el.msgid
        };

        if ("" === el.msgid) {
            // console.log("NO STRING");
        } else {
            // console.log("HERE WE ARE TRANSLATING:");
            // console.dir(el);
            // console.dir(i);
            // el.msgstr = "translation will go here";
            // translation_objects[i] = el;

            // translate.translateText(params, (err, data) => {
            //     console.log(chalk.white.bold("msgid: ") + chalk.white(el.msgid));
            //     if (err) console.log(err, err.stack); // an error occurred
            //     else {
            //         // successful response
            //         console.log(data);
            //         el.msgstr = data.TranslatedText;
            //         translation_objects[i] = el;
            //     }
            // });
        }
    });
}

sample_package.json

{
  "name": "mat_nib",
  "version": "1.0.0",
  "description": "A bespoke theme for NIB",
  "author": "Materiell",
  "license": "GPL-2.0",
  "private": true,
  "devDependencies": {
    "@babel/core": "^7.1.0",
    "@babel/preset-env": "^7.1.0",
    "chalk": "^2.4.1",
    "focus-within": "^2.0.0",
    "gulp": "github:gulpjs/gulp#v4.0.0",
    "gulp-autoprefixer": "^6.0.0",
    "gulp-babel": "^8.0.0",
    "gulp-cached": "^1.1.1",
    "gulp-concat": "^2.5.2",
    "gulp-cssnano": "^2.1.1",
    "gulp-filter": "^5.0.0",
    "gulp-imagemin": "^4.1.0",
    "gulp-jshint": "^2.1.0",
    "gulp-load-plugins": "^1.4.0",
    "gulp-newer": "^1.3.0",
    "gulp-plumber": "^1.0.1",
    "gulp-prettier": "^2.0.0",
    "gulp-remember": "^1.0.1",
    "gulp-sass": "^4.0.1",
    "gulp-sourcemaps": "^2.6.4",
    "gulp-uglify": "^3.0.1",
    "gulp-util": "^3.0.5",
    "gulp-wp-pot": "^2.0.4",
    "jshint": "^2.9.6",
    "jshint-stylish": "^2.0.0",
    "lodash": "^4.17.11",
    "pa11y": "^5.0.4"
  },
  "scripts": {
    "build": "gulp",
    "scripts": "gulp scripts",
    "styles": "gulp styles",
    "auto_translate": "gulp auto_translate",
    "translate": "gulp translate",
    "images": "gulp images",
    "pa11y": "gulp pa11y",
    "watch": "gulp watch"
  },
  "dependencies": {
    "aws-sdk": "^2.324.0",
    "gettext-parser": "^2.0.0"
  }
}