gulpfile.js

"use strict";

const gulp = require("gulp");

const NODE_SRC = "./src/**/*.js";
const NODE_DEST = "./lib";

const cli = require("commander")
  .usage("<task> [options]")
  .option(
    "-e, --env <environment>",
    "Can be `prod` or `dev`. Default is `dev`",
    /^(dev|prod)$/u,
    "dev"
  )
  .option(
    "-a, --analyze",
    "Analyze client bundle. If set, `env` will be set to `prod`."
  )
  .parse(process.argv);

const task = cli.args[0] || "watch";

gulp.task("clean", gulp.parallel(cleanNodeScripts, cleanViewerScripts));
gulp.task(
  "build",
  gulp.series("clean", compileNodeScripts, compileViewerScripts)
);
gulp.task("watch", gulp.series("build", watch));
gulp.task("default", gulp.task("watch"));

class TaskError extends Error {
  constructor(message) {
    super(message);
    this.name = "TaskError";
    // Internal Gulp flag that says "don't display error stack trace"
    this.showStack = false;
  }
}

function watch() {
  gulp
    .watch(NODE_SRC, gulp.series(cleanNodeScripts, compileNodeScripts))
    // TODO: replace with `emitErrors: false` option after https://github.com/gulpjs/glob-watcher/pull/34 will be merged
    .on("error", () => {});
}

function cleanViewerScripts() {
  const del = require("del");
  return del("public");
}

function cleanNodeScripts() {
  const del = require("del");
  return del(NODE_DEST);
}

function compileNodeScripts() {
  const babel = require("gulp-babel");

  return gulp.src(NODE_SRC).pipe(babel()).pipe(gulp.dest(NODE_DEST));
}

function compileViewerScripts() {
  const webpack = require("webpack");
  const config = require("./webpack.config")({
    env: cli.env,
    analyze: cli.analyze,
    watch: task === `dev`,
  });

  return new Promise((resolve, reject) => {
    webpack(config, (err, stats) => {
      if (cli.env === "dev") {
        if (err) {
          console.error(err);
        } else {
          console.log(stats.toString({ colors: true }));
        }
        resolve();
      } else {
        if (err) return reject(err);

        if (stats.hasErrors()) {
          reject(new TaskError("Webpack compilation error"));
        }

        console.log(stats.toString({ colors: true }));
        resolve();
      }
    });
  });
}