我有点搞不懂为什么我的gulp任务在文件更改时不运行。在控制台中，它检测到了更改，但实际上并没有重新运行任务。对于gulp来说，这是一个新手，所以希望能得到一些帮助。

const gulp = require('gulp');
const sass = require('gulp-sass')(require('sass'));
const autoprefixer = require('gulp-autoprefixer');
const browserSync = require('browser-sync').create();
const cleanCSS = require('gulp-clean-css');
const concat = require('gulp-concat');
const babel = require('gulp-babel');
const uglify = require('gulp-uglify');

// Compile Sass files and add vendor prefixes
function style() {
  return gulp
    .src('public/assets/css/*.css') // Source files
    .pipe(sass().on('error', sass.logError)) // Compile Sass to CSS
    .pipe(autoprefixer()) // Add vendor prefixes
    .pipe(cleanCSS()) // Minify CSS
    .pipe(concat('styles.css'))
    .pipe(gulp.dest('public/source/css')) // Output to destination folder
    .pipe(browserSync.stream()); // Inject changes into the browser
}

function scripts() {
    return gulp
      .src('public/assets/js/*.js')
      .pipe(babel({
        presets: ['@babel/env']
      }))
      .pipe(uglify()) // Minify JavaScript
      .pipe(concat('scripts.min.js'))
      .pipe(gulp.dest('public/source/js'))
      .pipe(browserSync.stream());
}

// Watch for changes in source files
function watch() {
  browserSync.init({
    proxy: "gif-ddev.ddev.site", // Your DDEV site URL
    files: ["public/assets/css/*.css", "public/assets/js/*.js"],
    open: true,
  });
  gulp.watch('public/assets/css/*.css', style); // Watch CSS files
  gulp.watch('public/assets/js/*.js', scripts); // Watch JS files
  gulp.watch(['templates/*.html', 'templates/**/*.twig']).on('change', browserSync.reload); // Watch HTML and Twig files
}

exports.style = style; // Expose the style task
exports.scripts = scripts;
exports.watch = watch; // Expose the watch task