Unexpected token keyword «function», expected punc «,»

[Nisthar]

I am getting Unexpected token keyword «function», expected punc «,» when i run npm run build

I am using vueify.

This is gulpfile.babel.js

import fs from "fs";
import gulp from "gulp";
import { merge } from "event-stream";
import browserify from "browserify";
import source from "vinyl-source-stream";
import buffer from "vinyl-buffer";
import preprocessify from "preprocessify";
import gulpif from "gulp-if";

const vueify = require("vueify");

const $ = require("gulp-load-plugins")();

const uglify = require("gulp-uglify");
const gulpUtil = require("gulp-util");
const ignore = require("gulp-ignore");

var production = process.env.NODE_ENV === "production";
var target = process.env.TARGET || "chrome";
var environment = process.env.NODE_ENV || "development";

var generic = JSON.parse(fs.readFileSync(`./config/${environment}.json`));
var specific = JSON.parse(fs.readFileSync(`./config/${target}.json`));
var context = Object.assign({}, generic, specific);

var manifest = {
  dev: {
    background: {
      scripts: ["scripts/livereload.js", "scripts/background.js"]
    }
  },

  firefox: {
    applications: {
      gecko: {
        id: "my-app-id@mozilla.org"
      }
    }
  }
};

// Tasks

gulp.task("clean", () => {
  return pipe(`./build/${target}`, $.clean());
});

gulp.task("build", cb => {
  $.runSequence("clean", "styles", "css", "fonts", "ext", cb);
});

gulp.task("watch", ["build"], () => {
  $.livereload.listen();

  gulp
    .watch(["./src/**/*", "./src/components/*", "./manifest.json"])
    .on("change", () => {
      $.runSequence("build", $.livereload.reload);
    });
});

gulp.task("default", ["build"]);

gulp.task("ext", ["manifest", "js"], () => {
  return mergeAll(target);
});

// -----------------
// COMMON
// -----------------
gulp.task("js", () => {
  return buildJS(target);
});

gulp.task("styles", () => {
  return gulp
    .src("src/styles/**/*.scss")
    .pipe($.plumber())
    .pipe(
      $.sass
        .sync({
          outputStyle: "expanded",
          precision: 10,
          includePaths: ["."]
        })
        .on("error", $.sass.logError)
    )
    .pipe(gulp.dest(`build/${target}/styles`));
});

gulp.task("css", () => {
  return gulp
    .src("src/styles/**/*.css")
    .pipe($.plumber())
    .pipe(gulp.dest(`build/${target}/styles`));
});

gulp.task("fonts", () => {
  return gulp
    .src("src/webfonts/**/*")
    .pipe($.plumber())
    .pipe(gulp.dest(`build/${target}/webfonts`));
});

gulp.task("manifest", () => {
  return gulp
    .src("./manifest.json")
    .pipe(
      gulpif(
        !production,
        $.mergeJson({
          fileName: "manifest.json",
          jsonSpace: " ".repeat(4),
          endObj: manifest.dev
        })
      )
    )
    .pipe(
      gulpif(
        target === "firefox",
        $.mergeJson({
          fileName: "manifest.json",
          jsonSpace: " ".repeat(4),
          endObj: manifest.firefox
        })
      )
    )
    .pipe(gulp.dest(`./build/${target}`));
});

// -----------------
// DIST
// -----------------
gulp.task("dist", cb => {
  $.runSequence("build", "zip", cb);
});

gulp.task("zip", () => {
  return pipe(`./build/${target}/**/*`, $.zip(`${target}.zip`), "./dist");
});

// Helpers
function pipe(src, ...transforms) {
  return transforms.reduce((stream, transform) => {
    const isDest = typeof transform === "string";
    return stream.pipe(isDest ? gulp.dest(transform) : transform);
  }, gulp.src(src));
}

function mergeAll(dest) {
  return merge(
    pipe("./src/icons/**/*", `./build/${dest}/icons`),
    pipe(["./src/_locales/**/*"], `./build/${dest}/_locales`),
    pipe([`./src/images/${target}/**/*`], `./build/${dest}/images`),
    pipe(["./src/images/shared/**/*"], `./build/${dest}/images`),
    pipe(["./src/**/*.html"], `./build/${dest}`)
  );
}

function buildJS(target) {
  const files = [
    "background.js",
    "contentscript.js",
    "options.js",
    "popup.js",
    "livereload.js",
    "app.js"
  ]; // "materialize.js",

  let tasks = files.map(file => {
    const dest = `build/${target}/scripts`;

    return browserify({ entries: "src/scripts/" + file, debug: true })
      .transform(vueify)
      .transform("babelify", {
        presets: [
          "es2015",
          [
            "env",
            {
              targets: {
                uglify: true
              }
            }
          ]
        ],
        plugins: [
          "transform-remove-console",
          "transform-es2015-shorthand-properties",
          "transform-class-properties",
          [
            "transform-runtime",
            {
              polyfill: false,
              regenerator: true
            }
          ]
        ]
      })
      .transform(preprocessify, {
        includeExtensions: [".js"],
        context: context
      })
      .bundle()
      .pipe(source(file))
      .pipe(buffer())
      .pipe(gulpif(!production, $.sourcemaps.init({ loadMaps: true })))
      .pipe(gulpif(!production, $.sourcemaps.write("./")))
      .pipe(ignore.exclude(["**/*.map"]))
      .pipe(
        gulpif(
          production,
          $.uglify({
            mangle: false,
            output: {
              ascii_only: true
            }
          })
        )
      )
      .pipe(gulp.dest(dest));
  });

  return merge.apply(null, tasks);
}

process.on("uncaughtException", function(err) {
  console.log(err);
});