Gulpfile.js

const path = require('path');
const fs = require('fs-extra');
const fsOrg = require("fs");
const gulp = require('gulp-help')(require('gulp'));
const gutil = require('gulp-util');
const webpack = require('webpack');
const watch = require('gulp-watch');
const gulpCopy = require('gulp-copy');
const sequence = require('gulp-sequence');
const del = require('del');

const banner = (color, banner) => gutil.colors[color || 'cyan'](banner ? `[${banner}]` : '[GULP]');

const pkg = require('./package.json');

// Set paths for our project folder

const projectPath = pkg.widget.path ? path.resolve(pkg.widget.path) + '/' : false;
const widgetsFolder = projectPath ? path.join(projectPath, `/widgets/`) : false;
const deploymentFolder = projectPath ? path.join(projectPath, `/deployment/web/widgets/`) : false;

// Check if project folder exists and is accessible

let stat = null;
if (!projectPath) {
    gutil.log(`${banner()} No testproject defined, only copying files to dist/build folder. Set project path in ${gutil.colors.cyan('widget.path')} in ${gutil.colors.magenta('package.json')}`);
} else {
    gutil.log(`${banner()} Testproject defined: ${gutil.colors.magenta(projectPath)}`);
    try {
        stat = projectPath ? fs.statSync(projectPath) : null;
    } catch (e) {
        gutil.log(`${banner('red')} Error getting project directory:`, e.toString());
        gutil.log(`${banner('red')} Copying to the project directory has been disabled`);
        stat = null;
    }
}

// Helper functions

const runWebpack = callback => {
    webpack(require('./webpack.config.js'), function (err, stats) {
        if (err) throw new gutil.PluginError("webpack", err);
        gutil.log(banner('cyan', 'WEBPACK'), stats.toString({
            colors: true,
            modules: false
        }));
        callback && callback();
    });
};

const copyFile = paths => {
    try {
        fs.copySync(paths.src, paths.dest);
    } catch (err) {
        gutil.log(`${banner('red')} Copy fail`, err);
    }
};

const getPaths = (file, srcFolder, destFolder) => {
    return {
        src: path.join(__dirname, srcFolder, file.relative),
        dest: path.join(destFolder, file.relative),
    }
}

// Base tasks

gulp.task('watch:src', () => {
    return watch('src/**/*', {
        verbose: true
    }, () => {
        runWebpack();
    })
});

gulp.task('watch:build', () => {
    return watch('build/**/*', {
        verbose: stat !== null,
        read: false
    }, file => {
        if (stat !== null) {
            const paths = getPaths(file, 'build', deploymentFolder);
            if (paths.src.indexOf('package.xml') !== -1) {
                return;
            }
            copyFile(paths);
        }
    })
});


// in the files which are copied to the dest folder there is bug, xml file are not included in the new copy.
// solved by set a webpack plugin to wirte the generated new zip/mpk to the project directory as well. 
/*
gulp.task('watch:dist', () => {
    return watch(`dist/${pkg.widget.package}.mpk`, {
        verbose: stat !== null,
        read: false
    }, file => {
        if (stat !== null) {
            const paths = getPaths(file, 'dist', widgetsFolder);
            copyFile(paths);

        }
    })
});

*/

gulp.task('clean', `Cleanup the dist/build`, () => {
    return del([
        'dist',
        'build'
    ], {
        force: true
    });
});

// Final tasks

gulp.task('build', 'Build the widget', done => {
    sequence('clean', 'build-dist', done);
});

gulp.task('build-dist', callback => {
    runWebpack(callback);
});

gulp.task('default', ['watch:src', 'watch:build']);