gulpfile.js

/* eslint-disable no-console */
/* eslint-env node */
'use strict';

const del = require('del');
const fs = require('fs');
const gulp = require('gulp');
const path = require('path');
const gulpif = require('gulp-if');
const uglifyes = require('uglify-es');
const composer = require('gulp-uglify/composer');
const cssSlam = require('css-slam').gulp;
const mergeStream = require('merge-stream');
const polymerBuild = require('polymer-build');
const browserSync = require('browser-sync').create();
const history = require('connect-history-api-fallback');
const eslint = require('gulp-eslint');
const friendlyFormatter = require('eslint-friendly-formatter');
const run = require('gulp-run');

const HtmlSplitter = polymerBuild.HtmlSplitter;
const PolymerProject = polymerBuild.PolymerProject;
const uglify = composer(uglifyes, console);

const config = {
  polymerJsonPath: './polymer.json',
  build: {
    rootDirectory: 'build',
  },
  swPrecacheConfigPath: './sw-precache-config.js',
  templateData: [
    `${getConfigPath()}`,
    'data/settings',
    'data/resources',
  ],
  tempDirectory: '.temp',
};

const swPrecacheConfig = require(config.swPrecacheConfigPath);
const polymerJson = require(config.polymerJsonPath);
const buildPolymerJson = {
  entrypoint: prependPath(config.tempDirectory, polymerJson.entrypoint),
  shell: prependPath(config.tempDirectory, polymerJson.shell),
  fragments: polymerJson.fragments.reduce((res, el) =>
    [...res, prependPath(config.tempDirectory, el)], []),
  sources: polymerJson.sources.reduce((res, el) =>
    [...res, prependPath(config.tempDirectory, el)], []),
  extraDependencies: polymerJson.extraDependencies,
};

const normalize = require('./gulp-tasks/normalize.js');
const template = require('./gulp-tasks/template.js');
// const images = require('./gulp-tasks/images.js');
const html = require('./gulp-tasks/html.js');


function build() {
  return new Promise((resolve) => {
    let polymerProject = null;
    console.log(`Deleting ${config.build.rootDirectory}` +
      ` and ${config.tempDirectory} directories...`);

    del([config.build.rootDirectory, config.tempDirectory])
      .then(() => {
        console.log(`Compiling template...`);

        const compileStream = template.compile(config, polymerJson)
          .on('end', () => {
            polymerProject = new PolymerProject(buildPolymerJson);
          });
        return waitFor(compileStream);
      })
      .then(() => {
        console.log(`Polymer building...`);

        const sourcesHtmlSplitter = new HtmlSplitter();
        const sourcesStream = polymerProject.sources()
          .pipe(sourcesHtmlSplitter.split())
          // .pipe(gulpif(/\.js$/, uglify()))
          .pipe(gulpif(/\.(html|css)$/, cssSlam()))
          .pipe(gulpif(/\.html$/, html.minify()))
          // .pipe(gulpif(/\.(png|gif|jpg|svg)$/, images.minify()))
          .pipe(sourcesHtmlSplitter.rejoin());

        const dependenciesHtmlSplitter = new HtmlSplitter();
        const dependenciesStream = polymerProject.dependencies()
          .pipe(dependenciesHtmlSplitter.split())
          // Doesn't work for now
          // .pipe(gulpif(/\.js$/, uglify()))
          .pipe(gulpif(/\.(html|css)$/, cssSlam()))
          .pipe(gulpif(/\.html$/, html.minify()))
          .pipe(dependenciesHtmlSplitter.rejoin());

        let buildStream = mergeStream(sourcesStream, dependenciesStream)
          .once('data', () => {
            console.log('Analyzing and optimizing...');
          });

        buildStream = buildStream.pipe(polymerProject.bundler({
          stripComments: true,
        }));
        buildStream = buildStream.pipe(gulp.dest(config.build.rootDirectory));
        return waitFor(buildStream);
      })
      .then(() => {
        console.log('Generating the Service Worker...');

        return polymerBuild.addServiceWorker({
          project: polymerProject,
          buildRoot: prependPath(
            config.build.rootDirectory,
            config.tempDirectory
          )
            .replace('\\', '/'),
          bundled: config.build.bundled,
          swPrecacheConfig,
        });
      })
      .then(() => {
        console.log('Normalizing...');

        const normalizeStream = normalize(config)
          .on('end', () => {
            del([prependPath(
              config.build.rootDirectory,
              config.tempDirectory
            )]);
          });

        return waitFor(normalizeStream);
      })
      .then(() => {
        return gulp.src(prependPath(
          config.build.rootDirectory,
          'service-worker.js'
        ))
          .pipe(uglify())
          .pipe(gulp.dest(config.build.rootDirectory));
      })
      .then(() => {
        console.log('Build complete!');
        resolve();
      });
  });
}

function lint() {
  return gulp.src([
    `scripts/**/*.js`,
    `src/**/*.{html,js}`,
    'index.html',
  ])
    .pipe(eslint())
    .pipe(eslint.format(friendlyFormatter))
    .pipe(eslint.failAfterError());
}

function deploy() {
  let metadata = {};
  for (let file of config.templateData) {
    metadata = Object.assign({}, metadata, require(path.join(process.cwd(), file)));
  }
  return run(`firebase use ${metadata.firebase.projectId} && firebase deploy`).exec();
}

function waitFor(stream) {
  return new Promise((resolve, reject) => {
    stream.on('end', resolve);
    stream.on('error', reject);
  });
}

function reload(done) {
  browserSync.reload();
  done();
}

function compileTemplate() {
  return del([config.tempDirectory])
    .then(() => {
      return waitFor(template.compile(config, polymerJson));
    });
}

function copyStatic() {
  return gulp.src([
    'data/**/*.{markdown,md}',
    'images/**/*.{png,gif,jpg,svg}',
  ], {
    base: '.',
  })
    .pipe(gulp.dest(config.tempDirectory));
}

function prependPath(pre, to) {
  return `${pre}/${to}`;
}

function getConfigPath() {
  const path = process.env.BUILD_ENV ? `config/${process.env.BUILD_ENV}` : 'config/development';

  if (!fs.existsSync(`${path}.json`)) {
    console.error(`ERROR: Config path '${path}' does not exists. Please, add/use production|development.json files.`);
    return null;
  }

  console.log(`File path ${path}.json selected as config...`);
  return path;
}

gulp.task('default', build);
gulp.task('default', gulp.series(lint, build));

gulp.task('lint', lint);
gulp.task('deploy', deploy);

gulp.task('serve', gulp.series(compileTemplate, () => {
  browserSync.init({
    logPrefix: 'Hoverboard 2',
    notify: false,
    server: {
      baseDir: [config.tempDirectory, './'],
      middleware: [history()],
    },
  });

  gulp.watch([
    'data/**/*.{markdown,md}',
    'images/**/*.{png,gif,jpg,svg}',
  ], gulp.series(copyStatic, reload));

  gulp.watch([
    'data/**/*.json',
    'scripts/**/*.js',
    'src/**/*.html',
    '*.{html,js}',
    'manifest.json',
  ], gulp.series(compileTemplate, reload));
}));