How to solve this ?

[anjkt]

I m getting this error while hitting npm run build

[ozasadnyy]

it's gulp related issue: gulpjs/gulp#2065
Also, we had such issue here: #356

[anjkt]

I had fixed up the above Please Help me for this I am getting this error again

[anjkt]

'use strict';

const del = require('del');
const gulp = require('gulp');
const gulpif = require('gulp-if');
const uglify = require('gulp-uglify');
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 logging = require('plylog');
// logging.setVerbose();

const config = {
polymerJsonPath: './polymer.json',
build: {
rootDirectory: 'build',
bundled: true
},
swPrecacheConfigPath: './sw-precache-config.js',
templateData: [
'data/hoverboard.config',
'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;
let sourcesStreamSplitter = new polymerBuild.HtmlSplitter();
let dependenciesStreamSplitter = new polymerBuild.HtmlSplitter();

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 polymerBuild.PolymerProject(buildPolymerJson);
      });
    return waitFor(compileStream);
  })
  .then(() => {
    console.log(`Polymer building...`);

    const sourcesStream = polymerProject.sources()
      .pipe(gulpif(/\.(png|gif|jpg|svg)$/, images.minify()))
      .pipe(sourcesStreamSplitter.split())
      // splitHtml doesn't split CSS https://github.com/Polymer/polymer-build/issues/32
      .pipe(gulpif(/\.js$/, uglify()))
      .pipe(gulpif(/\.(html|css)$/, cssSlam()))
      .pipe(gulpif(/\.html$/, html.minify()))
      .pipe(sourcesStreamSplitter.rejoin());

    const dependenciesStream = polymerProject.dependencies()
      .pipe(dependenciesStreamSplitter.split())
      .pipe(gulpif(/\.js$/, uglify()))
      .pipe(gulpif(/\.(html|css)$/, cssSlam()))
      .pipe(gulpif(/\.html$/, html.minify()))
      .pipe(dependenciesStreamSplitter.rejoin());

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

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

function copyAndReload(file) {
const dest = prependPath(config.tempDirectory, file.substring(0, file.lastIndexOf('/')))

gulp.src(file).pipe(gulp.dest(dest));

browserSync.reload();
}

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

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

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

gulp.task('default', build);

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

gulp.watch([
'data//*.{markdown,md}',
'images//*.{png,gif,jpg,svg}',
]).on('change', copyAndReload);

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

[ozasadnyy]

Try to install gulp v4 https://github.com/gulpjs/gulp/releases/tag/v4.0.0