gulpfile.js

const gulp = require("gulp");
const uglify = require("gulp-uglify-es").default;
const ts = require("gulp-typescript");
const tsify = require("tsify");
const browserify = require("browserify");
const rename = require("gulp-rename");
const source = require("vinyl-source-stream");
const buffer = require("vinyl-buffer");
const shakeify = require("common-shakeify");
const { merge } = require("event-stream");

function bundle(file, release) {
    const options = { project: "tsconfig.json" };

    if (release)
        options.target = "es5";

    return browserify(file)
        .plugin(tsify, options)
        .plugin(shakeify)
        .bundle()
        .pipe(source("instascan.js"));
}

function build(opts) {
    const project = ts.createProject("tsconfig.json", opts);

    return gulp.src(["./src/**.ts", "!./src/instascan.ts"])
        .pipe(project());
}

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

gulp.task("watch", ["build"], function () {
    gulp.watch("./src/*.ts", ["build"]);
});

gulp.task("release", function () {
    const tsOptions = {
        target: "es5",
        declaration: true,
        declarationDir: "./dist"
    };
    const uglifyOptions = {
        toplevel: true,
        compress: {
            toplevel: true
        },
        nameCache: {}
    };
    const { js, dts } = build(tsOptions);
    const jsStream = js
        .pipe(uglify(uglifyOptions))
        .pipe(gulp.dest("./dist"));
    const dtsStream = dts
        .pipe(gulp.dest("./dist"));
    const bundleStream = bundle("./src/instascan.ts")
        .pipe(buffer())
        .pipe(uglify(uglifyOptions))
        .pipe(rename({ suffix: ".min" }))
        .on("error", function (err) { console.log(err.toString()); })
        .pipe(gulp.dest("./dist"));

    return merge([jsStream, dtsStream, bundleStream]);
});

gulp.task("build", function () {
    const { js, dts } = build();
    const jsStream = js.pipe(gulp.dest("./dist"));
    const dtsStream = dts.pipe(gulp.dest("./dist"));
    const bundleStream = bundle("./src/instascan.ts").pipe(gulp.dest("./dist"));

    return merge([jsStream, dtsStream, bundleStream]);
});