In the project directory, you can run:
Runs the app in the development mode.
Open http://localhost:3000 to view it in the browser.
The page will reload if you make edits.
You will also see any lint errors in the console.
Launches the test runner in the interactive watch mode.
See the section about running tests for more information.
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.
Your app is ready to be deployed!
See the section about deployment for more information.
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) right into your project so you have full control over them. 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 uses the latest version of React.
You can refer to the React documentation for more information about supported browsers.
This feature is currently only supported by Visual Studio Code and WebStorm.
Visual Studio Code and WebStorm support debugging out of the box with Create React App. This enables you as a developer to write and debug your React code without leaving the editor, and most importantly it enables you to have a continuous development workflow, where context switching is minimal, as you don’t have to switch between tools.
You would need to have the latest version of VS Code and VS Code Chrome Debugger Extension installed.
Then add the block below to your launch.json
file and put it inside the .vscode
folder in your app’s root directory.
{
"version": "0.2.0",
"configurations": [{
"name": "Chrome",
"type": "chrome",
"request": "launch",
"url": "http://localhost:3000",
"webRoot": "${workspaceRoot}/src",
"sourceMapPathOverrides": {
"webpack:///src/*": "${webRoot}/*"
}
}]
}
Note: the URL may be different if you've made adjustments via the HOST or PORT environment variables.
Start your app by running npm start
, and start debugging in VS Code by pressing F5
or by clicking the green debug icon. You can now write code, set breakpoints, make changes to the code, and debug your newly modified code—all from your editor.
Having problems with VS Code Debugging? Please see their troubleshooting guide.
The generated project includes React and ReactDOM as dependencies. It also includes a set of scripts used by Create React App as a development dependency. You may install other dependencies (for example, React Router) with npm
:
npm install --save react-router
Alternatively you may use yarn
:
yarn add react-router
This works for any library, not just react-router
.
This project uses the react particle background component library https://github.com/lindelof/particles-bg. It's very simple. Anyone can be a Musketeer with it.
Instead of downloading the entire app before users can use it, code splitting allows you to split your code into small chunks which you can then load on demand.
This project setup supports code splitting via dynamic import()
. Its proposal is in stage 3. The import()
function-like form takes the module name as an argument and returns a Promise
which always resolves to the namespace object of the module.
Check out this tutorial. You can find the companion GitHub repository here.
To create tests, add it()
(or test()
) blocks with the name of the test and its code. You may optionally wrap them in describe()
blocks for logical grouping but this is neither required nor recommended.
Jest provides a built-in expect()
global function for making assertions.
By default, the production build is a fully functional, offline-first Progressive Web App.
Source map explorer analyzes JavaScript bundles using the source maps. This helps you understand where code bloat is coming from.