gulp + typescript + css + autorebuild

gulpfile.js

const gulp = require("gulp");
const sourcemaps = require("gulp-sourcemaps");
const ts = require("gulp-typescript");
const tsProject = ts.createProject("tsconfig.json");

const cssInput = "src/**/*.css";
const output = "out";

function typescript(cb) {
  tsProject
    .src()
    .pipe(sourcemaps.init())
    .pipe(tsProject())
    .on("error", () => {})
    .js.pipe(sourcemaps.write())
    .pipe(gulp.dest(output));
  cb();
}

function css(cb) {
  gulp.src(cssInput).pipe(gulp.dest(output));

  cb();
}

exports.default = function() {
  gulp.series(css, typescript);
};

gulp.task("watch", watch);

function watch(cb) {
  gulp.watch(cssInput, { ignoreInitial: false }, css);
  gulp.watch(
    ["src/**/*.ts", "src/**/*.tsx"],
    { ignoreInitial: false },
    typescript
  );
}

package.json

{
  "name": "xx",
  "displayName": "xxxx",
  "description": "xxxx xxxx",
  "version": "0.0.1",
  "categories": [
    "Other"
  ],
  "main": "./out/extension.js",
  "scripts": {
    "build": "gulp",
    "compile": "gulp",
    "watch": "gulp watch",
    "pretest": "yarn run compile"
  },
  "devDependencies": {
    "@types/node": "^12.6.8",
    "@types/react": "^16.7.18",
    "@types/react-dom": "^16.0.11",
    "electron": "5.0.6",
    "gulp": "^4.0.2",
    "gulp-sourcemaps": "^2.6.5",
    "gulp-typescript": "^5.0.1",
    "typescript": "^3.3.1"
  },
  "license": "MIT"
}

tsconfig.json

{
  "compilerOptions": {
    "experimentalDecorators": true,
    "module": "commonjs",
    "target": "es6",
    "outDir": "out",
    "moduleResolution": "node",
    "jsx": "react",
    "lib": [
      "es6", "dom"
    ],
    "sourceMap": true,
    "rootDir": "src",
    "resolveJsonModule": true
  },
  "exclude": [
    "node_modules"
  ]
}