NPM and Gulp for Asp.Net Core 3 config sample

gulpfile.js

/// <binding AfterBuild='default' Clean='clean' />
/*
This file is the main entry point for defining Gulp tasks and using Gulp plugins.
Click here to learn more. http://go.microsoft.com/fwlink/?LinkId=518007
*/

var gulp = require('gulp');
var del = require('del');
var plumber = require('gulp-plumber');
var concat = require('gulp-concat');
var rename = require('gulp-rename');
var uglify = require('gulp-uglify');
var sourcemaps = require('gulp-sourcemaps');
var merge = require('merge-stream');

var nodeRoot   = './node_modules/';
var wwwroot = './wwwroot/';
var libTargetPath = wwwroot +'lib/';
var jsBundleTarget = wwwroot + 'js/bundle/';

var mainJSLib = { 
    sources: [ 
        nodeRoot + "jquery/dist/jquery.js",
        nodeRoot + "bootstrap/dist/js/bootstrap.bundle.js",
        wwwroot + "js/**/*.js"
    ],
    dest: libTargetPath + "main/js"
};

var validationJSLib = { 
    sources: [ 
        nodeRoot + "jquery-validation/dist/jquery.validate.js",
        nodeRoot + "jquery-validation-unobtrusive-bootstrap/dist/unobtrusive-bootstrap.js"
    ],
    dest: libTargetPath + "validation/js"
};

var libFiles = [ mainJSLib, validationJSLib ];

var appBundles = [
    { sources: [ libTargetPath + "main/js/**/*.js" ], output: 'site.main.bundle.js' },
    { sources: [ libTargetPath + "validation/js/**/*.js" ], output: 'site.validation.bundle.js' }
];

function clean() {
    return del([libTargetPath + '/**/*', jsBundleTarget + '/**/*']);
}

function moveLibFiles() {
    var streams = [];
    libFiles.forEach(function (libFile) {
        console.log('Moving lib files from: ' + libFile.sources + ' into: ' + libFile.dest);
        var stream = gulp.src(libFile.sources)
        .pipe(plumber())
        .pipe(gulp.dest(libFile.dest))
        .on('error', errorHandler);
        streams.push(stream);
    });
    return merge.apply(this, streams);
};

function minify() {
    var streams = [];
    appBundles.forEach(function (appBundle) {
        console.log('Creating minified files for: ' + appBundle.sources + ' into: ' + jsBundleTarget + appBundle.output);
        var stream = gulp.src(appBundle.sources)
            .pipe(plumber())
            .pipe(concat(appBundle.output))
            .pipe(rename({ extname: '.min.js' }))
            .pipe(uglify())
            .pipe(gulp.dest(jsBundleTarget))
            .on('error', errorHandler);
        streams.push(stream);
    });
    return merge.apply(this, streams);
}

function bundle() {
    var streams = [];
    appBundles.forEach(function (appBundle) {
        console.log('Creating bundle and sourcemaps: ' + jsBundleTarget + appBundle.output);
        var stream = gulp.src(appBundle.sources)
            .pipe(plumber())
            .pipe(concat(appBundle.output))
            .pipe(sourcemaps.init())
            .pipe(sourcemaps.write('.'))
            .pipe(gulp.dest(jsBundleTarget))
            .on('error', errorHandler);
        streams.push(stream);
    });
    return merge.apply(this, streams);
};

function errorHandler(error) {
    console.error(error.toString());
    process.exit(-1);
}

exports.default = gulp.series(clean, moveLibFiles, minify, bundle);

package.json

{
  "version": "1.0.0",
  "name": "aspnetmvc",
  "private": true,
  "devDependencies": {
    "del": "^5.1.0",
    "gulp": "^4.0.2",
    "gulp-concat": "^2.6.1",
    "gulp-plumber": "^1.2.1",
    "gulp-rename": "^2.0.0",
    "gulp-sourcemaps": "^2.6.5",
    "gulp-uglify": "^3.0.2",
    "merge-stream": "^2.0.0"
  },
  "dependencies": {
    "bootstrap": "^4.4.1",
    "cldr-data": "^36.0.0",
    "cldr": "^5.6.0",
    "globalize": "^1.5.0",
    "jquery-mask-plugin": "^1.14.16",
    "jquery-validation-globalize-fix": "^0.1.1",
    "jquery-validation-unobtrusive-bootstrap": "^2.2.0",
    "jquery-validation": "^1.19.1",
    "jquery": "^3.5.0"
  }
}