sync-deletes.es6

'use strict';
const path        = require('path');
const del         = require('del');
const gulp        = require('gulp');
const watch       = require('gulp-watch');

const FILE_SRC_GLOB       = ['src/**/*'];
const FILE_SRC_GLOB_NO_JS = [FILE_SRC_GLOB[0], `!${FILE_SRC_GLOB[0]}.js`];
const FILE_DEST_GLOB      = 'app';

const JS_SRC_GLOB = [`${FILE_SRC_GLOB[0]}.js`];
const JS_DEST_DIR = FILE_DEST_GLOB;

function destPathFromSrc(srcGlob, destGlob, srcPath) {
    return path.resolve(destGlob, path.relative(path.resolve(srcGlob), srcPath));
}

gulp.task('watch:sync-deletes', () => {
    return new Promise((resolve, reject) => {
        watch(FILE_SRC_GLOB, {name: 'watch:sync-deletes', ignoreInitial: true, events: ['unlink'], read: false}, vinylFile => {
            let destPath = destPathFromSrc('src', FILE_DEST_GLOB, vinylFile.path);
            del(destPath);
            // Handle removal of sourcemaps
            if (path.extname(vinylFile.path) == '.js') {
                del(destPath + '.map');
            }
        });
    });
});