build.js

"use strict";
const gulp = require("gulp");
var plumber = require("gulp-plumber");
var sass = require("gulp-sass");
var sourcemaps = require("gulp-sourcemaps");
var exec = require("gulp-exec");
var rename = require("gulp-rename");
var tap = require("gulp-tap");
var handlebars = require("handlebars");
var glob = require("glob");
var fs = require("fs");
var path = require("path");
var pkg = require("../package.json");
var dirs = pkg.directories;
var gprint = require("gulp-print");
const electronRebuild = require("electron-rebuild");
let childProcess = require("child_process");
let pathToElectron = require("electron-prebuilt");

gulp.task("build:app", function() {
	//TODO: copy dependencies from top-level package.json and copy to src/package.json
	gulp.src(dirs.src+"/**/*.json")
		.pipe(gulp.dest(dirs.build));
});

gulp.task("build:sass", function() {
	gulp.src(dirs.src+"/**/*.{sass,scss}")
		.pipe(plumber())
		.pipe(sourcemaps.init())
		.pipe(sass().on("error", sass.logError))
		.pipe(sourcemaps.write("./"))
		.pipe(gulp.dest(dirs.build));
});

gulp.task("build:gs", function() {
	let options = {
		continueOnError: false,
		pipeStdout: true
	};
	gulp.src(dirs.src+"/**/*.gs")
		.pipe(plumber())
		.pipe(exec("guavac \"<%= file.path %>\"", options))
		.pipe(rename(function(path) {
			path.extname = ".js";
		}))
		.pipe(gulp.dest(dirs.build));
});

gulp.task("build:js", function() {
	gulp.src(dirs.src+"/**/*.js").pipe(gulp.dest(dirs.build));
});

gulp.task("build:html", function() {
	const partialExt = ".partial.html";
	let partialFiles = glob.sync(dirs.src+"/**/*"+partialExt);
	partialFiles.forEach(function(filename) {
		var name = path.basename(filename, partialExt);
		console.log("Using partial: "+name+" ("+filename+")");
		var partial = fs.readFileSync(filename, "utf8");
		handlebars.registerPartial(name, partial);
	});
	
	gulp.src([
		dirs.src+"/**/*.html",
		"!"+dirs.src+"/**/*.partial.html"
	])
		.pipe(plumber())
		//.pipe(handlebars({}))
		.pipe(tap(function(file) {
			var template  = handlebars.compile(file.contents.toString());
			var html = template({});
			file.contents = new Buffer(html);
		}))
		.pipe(gulp.dest(dirs.build));
});

gulp.task("build:resources", function() {
	gulp.src(dirs.src+"/resources/**/*.{woff,ttf,png,jpg}")
		.pipe(gulp.dest(dirs.build+"/resources"));
});

gulp.task("watch", function() {
	gulp.watch(dirs.src+"/**/*.json", ["build:app"]);
	gulp.watch(dirs.src+"/**/*.{sass,scss}", ["build:sass"]);
	gulp.watch(dirs.src+"/**/*.gs", ["build:gs"]);
	gulp.watch(dirs.src+"/**/*.js", ["build:js"]);
	gulp.watch(dirs.src+"/**/*.html", ["build:html"]);
	gulp.watch(dirs.src+"/resources/**/*.{woff,ttf,png,jpg}", ["build:resources"]);
});

gulp.task("rebuild", function() {
	electronRebuild.shouldRebuildNativeModules(pathToElectron)
		.then((shouldBuild) => {
			if (!shouldBuild) {
				return true;
			}
			
			console.log("Rebuilding...");
			let electronVersion = childProcess.execSync(`"${pathToElectron}" --version`, {encoding: "utf8"});
			electronVersion = electronVersion.match(/v(\d+\.\d+\.\d+)/)[1];
			console.log(`  Electron version: ${electronVersion}`);
			
			return electronRebuild.installNodeHeaders(electronVersion)
				.then(() => electronRebuild.rebuildNativeModules(electronVersion, "./build/node_modules"))
				.then(() => electronRebuild.preGypFixRun("./build/node_modules", true, pathToElectron));
		})
		.catch((e) => {
			console.error("Building modules didn't work!");
			console.error(e);
		});
});

gulp.task("build", ["build:app", "build:sass", "build:gs", "build:js", "build:html", "build:resources"]);
gulp.task("fullbuild", ["build", "rebuild"]);

gulpfile.js

"use strict";

require("./tasks/build");
require("./tasks/start");

package.json

{
  ...
  "scripts": {
    "build": "gulp build",
    "start": "gulp start"
  },
  "devDependencies": {
    ...
    "glob": "^7.1.1",
    "gulp": "3.9.1",
    "gulp-batch": "1.0.5",
    "gulp-exec": "2.1.2",
    "gulp-mocha": "3.0.1",
    "gulp-plumber": "1.1.0",
    "gulp-rename": "1.2.2",
    "gulp-sass": "2.3.2",
    "gulp-sourcemaps": "1.6.0",
    "gulp-tap": "0.1.3",
    "handlebars": "4.0.6"
  },
  "directories": {
    "src": "src",
    "build": "build",
    "dist": "dist"
  }
}

start.js

"use strict";
const childProcess = require("child_process");
const electron = require("electron-prebuilt");
const gulp = require("gulp");

var build_dir = "./build";

gulp.task("start", ["build", "watch"], function () {
	childProcess.spawn(electron, [build_dir], {
		stdio: "inherit"
	})
	.on("close", function() {
		process.exit();
	})
	.on("error", function() {
		console.log("Closed due to error")
	});
});