Modern Javascript Development

1. Module => Bundling => Transpiling / Polyfilling|babel(convert to es5) => Javascript Bundle.

Build tools webpack hard to build or Parcel easy to build for production

Parcel

sudo npm i parcel
npm i parcel --save-dev
npx parcel index.html

npm uninstall parcel

if(module.hot) {
  module.hot.accept()
}

Transpiling

.json  "script": {
  "start": "parcel index.html",
  "build": "parcel build index.html"
}
1. `"parcel build index.html --dist-dir ./dist"`
cmd=> `npm run build`

Polyfilling

npm i core-js

import script.js file| import 'core-js/stable';
// import 'core-js/stable/array/find';
// import 'core-js/stable/promise';

cmd$ npm i regenerator-runtime
// Polifilling async function
import 'regenerator-runtime/runtime';

---

git controls

gitignore .gitignore node_modules dist .parcel-cache | .DS_store > for macOS

GIT

• git: git add -A, git status, git reset --hard HEAD(back to previous git add file)
• git log(copy-commit id) then, git reset -hard demo83896EXAMPLE733974cde (back to previous commit code)
• git branch new-feature(new branch create), git checkout new-feature(switch branch), git checkout master(switch branch if merge code from new-feature branch), git merge new-feature , git push origin new-feature (branch push)
• git cheat sheet

Removing the last commit

• If you want to "uncommit" the commits, but keep the changes around for reworking, remove the "--hard": git reset HEAD^ which will evict the commits from the branch and from the index, but leave the working tree around.

• To remove the last commit from git, you can simply run git reset --hard HEAD^ If you are removing multiple commits from the top, you can run git reset --hard HEAD~2 to remove the last two commits. You can increase the number to remove even more commits.

• If you want to save the commits on a new branch name, then run git branch newbranchname before doing the git reset.

Netlify: config your build, build command >parcel build index.html --dist-dir ./dist , publish-directory> dist

Module

• Reusable piece of code that encapsulates implementation details;
• Usually a standalone file, but it doesn't have to be.
• Compose software: Modules are small building blocks that we put together to build complex applications;
• Isolate components: Modules can be developed in isolation without thinking about the entire codebase;
• Abstract code: Implement low-level code in modules and import these abstractions into other modules;
• Organized code: Modules naturally lead to a more organized codebase;
• Reuse code: Modules allow us to easily reuse the same code, even across multiple projects.

Importing Modules before execution

• Modules are imported synchronously
• Possible thanks to top-level("static") imports, which make imports known before execution
• This makes bundling and dead code elimination possible

---

<script type="module" defer src="script.js"></script>

• ES modules, two types of exports. Named Exports and Default Exports. Named Exports:

import './shoppingCart';
import { addToCart, totalPrice as price, tq } from './shoppingCart';
import * as ShoppingCart from './shoppingCart.js';

Default Export

export default function (product, quantity) {};
import add from './shoppingCart';
add('pizza', 2);

• didn't use strict mode module have default

One time function | not reuse it

(function() {

})();