portfolio/gulpfile.js

var gulp = require('gulp');
var sass = require('gulp-sass');
var babel = require('gulp-babel');
var concat = require('gulp-concat');
var rename = require('gulp-rename');
var uglify = require('gulp-uglify');
var rollup = require('rollup-stream');
var sourcemaps = require('gulp-sourcemaps');
var browserSync = require('browser-sync');
var jsonld = require('jsonld');
var source = require('vinyl-source-stream');
var buffer = require('vinyl-buffer');


var through = require('through2')
// todo: rollup for d3 & possibly jsonld

var paths = {
  "styles": {
    "src": "./src/scss/*.scss",
    "dest": "./assets/css/"
  },
  "scripts": {
    "src": "./src/js/portfolio.js",
    "dest": "./assets/js/",
    "d3src": "./src/js/d3.bundle.js",
    "d3destDir": "./assets/js/"
  },
  "data": {
    "src": "./rubenvandeven.jsonld",
    "dest": "./assets/js/"
  }
};

gulp.task('styles', function() {
  gulp.src(paths.styles.src, { sourcemaps: true })
      .pipe(sass().on('error', sass.logError))
      .pipe(gulp.dest(paths.styles.dest))
      .pipe(browserSync.reload({ stream: true }));
});


gulp.task('scripts', function() {
    return gulp.src(paths.scripts.src)
      .pipe(sourcemaps.init())
      .pipe(babel({
            ignore: [
                './src/js/d3.v5.js',
            ]
          }))
      .pipe(concat('portfolio.js'))
      .pipe(gulp.dest(paths.scripts.dest)) // save .js
      .pipe(uglify())
      .pipe(rename({ extname: '.min.js' }))
      // .pipe(sourcemaps.write('maps'))
      .pipe(gulp.dest(paths.scripts.d3destDir)) // save .min.js
});

gulp.task('d3', function() {
    return rollup( 'rollup.config.js' )
      .pipe(source('d3.bundle.js'))
      .pipe(gulp.dest(paths.scripts.d3destDir)) // save .js
      .pipe(buffer())
      .pipe(uglify())
      .pipe(rename({ extname: '.min.js' }))
      .pipe(sourcemaps.write('maps'))
      .pipe(gulp.dest(paths.scripts.d3destDir)) // save .min.js
});

gulp.task('jsonld', function(){
  return gulp.src(paths.data.src)
    .pipe(through.obj(function (file, enc, callback) {
      let data = JSON.parse(file.contents.toString(enc));
      var transformedFile = file.clone();
      // console.log(data);
      jsonld.flatten(data, {}, (err, flattened)=> {
        transformedFile.contents = Buffer.from(JSON.stringify(flattened), enc);
        callback(null, transformedFile)
      });
    }))
    .pipe(gulp.dest(paths.data.dest));
});

var watchStylesAndScripts = function() {
  gulp.watch(paths.styles.src,['styles']);
  gulp.watch(paths.scripts.src,['scripts', browserSync.reload]);
  gulp.watch(paths.scripts.d3src,['d3', browserSync.reload]);
  gulp.watch([paths.data.src], ['jsonld', browserSync.reload]);
}

gulp.task('watch', watchStylesAndScripts);

// watch files for changes and reload
gulp.task('serve', function() {
  browserSync({
    server: {
      baseDir: '.'
    }
  });

  gulp.watch(['index.html','rubenvandeven.jsonld'], browserSync.reload({stream: true}));
  watchStylesAndScripts();
});


gulp.task('default', function() {
   gulp.parallel('styles', 'scripts');
});