CLI tools Flashcards
If you’ve previously installed create-react-app globally via npm install -g create-react-app
Create React App is an officially supported way to create single-page React applications. It offers a modern build setup with no configuration.
npx create-react-app my-app
cd my-app
npm start
When you’re ready to deploy to production, create a minified bundle with npm run build.
You’ll need to have Node >= 14 on your local development machine (but it’s not required on the server). You can use nvm (macOS/Linux) or nvm-windows to switch Node versions between different projects.
To create a new app, you may choose one of the following methods:
npx
npx create-react-app my-app
(npx comes with npm 5.2+ and higher, see instructions for older npm versions)
npm
npm init react-app my-app
npm init <initializer> is available in npm 6+</initializer>
You can now optionally start a new app from a template by appending –template [template-name] to the creation command.
If you don’t select a template, we’ll create your project with our base template.
You can start a new TypeScript app using templates. To use our provided TypeScript template, append –template typescript to the creation command.
npx create-react-app my-app –template typescript
npm start or yarn start
Runs the app in development mode. Open http://localhost:3000 to view it in the browser.
npm run build or yarn build
Builds the app for production to the build folder. It correctly bundles React in production mode and optimizes the build for the best performance.
The build is minified and the filenames include the hashes.
You may create subdirectories inside src. For faster rebuilds, only files inside src are processed by webpack. You need to put any JS and CSS files inside src, otherwise webpack won’t see them.
Only files inside public can be used from public/index.html. Read instructions below for using assets from JavaScript and HTML.
You can, however, create more top-level directories. They will not be included in the production build so you can use them for things like documentation.
If you have Git installed and your project is not part of a larger repository, then a new repository will be initialized resulting in an additional top-level .git directory.
npm run eject
Note: this is a one-way operation. Once you eject, you can’t go back!
If you aren’t satisfied with the build tool and configuration choices, you can eject at any time. This command will remove the single build dependency from your project.
Instead, it will copy all the configuration files and the transitive dependencies (webpack, Babel, ESLint, etc.) into your project as dependencies in package.json. Technically, the distinction between dependencies and development dependencies is pretty arbitrary for front-end apps that produce static bundles.
In addition, it used to cause problems with some hosting platforms that didn’t install development dependencies (and thus weren’t able to build the project on the server or test it right before deployment). You are free to rearrange your dependencies in package.json as you see fit.
All of the commands except eject will still work, but they will point to the copied scripts so you can tweak them. At this point you’re on your own.
You don’t have to ever use eject. The curated feature set is suitable for small and middle deployments, and you shouldn’t feel obligated to use this feature. However we understand that this tool wouldn’t be useful if you couldn’t customize it when you are ready for it.
By default, the generated project supports all modern browsers. Support for Internet Explorer 9, 10, and 11 requires polyfills. For a set of polyfills to support older browsers, use npm install react-app-polyfill
When you run npx create-react-app my-app it automatically installs the latest version of Create React App.
To update an existing project to a new version of react-scripts, open the changelog, find the version you’re currently on (check package.json in this folder if you’re not sure), and apply the migration instructions for the newer versions.
In most cases bumping the react-scripts version in package.json and running npm install (or yarn install) in this folder should be enough, but it’s good to consult the changelog for potential breaking changes.
Prettier is an opinionated code formatter with support for JavaScript, CSS and JSON. With Prettier you can format the code you write automatically to ensure a code style within your project. See Prettier’s GitHub page for more information, and look at this page to see it in action.
To format our code whenever we make a commit in git, we need to install the following dependencies:
npm install –save husky lint-staged prettier
husky makes it possible to use githooks as if they are npm scripts.
lint-staged allows us to run scripts on staged files in git. See this blog post about lint-staged to learn more about it.
prettier is the JavaScript formatter we will run before commits.
