3. Using the Generator

Once the application is generated inside your project's directory and all dependencies are installed, you can run the following commands to run, build and test the app:

npm start

This will run the app in development mode in a local server.
Visit http://localhost:3000 to run and view the app.

HMR (Hot Module Replacement) is being used to update modules whenever there is a change in code, hence your changes will be shown automatically. Build errors and lint errors are also shown in the console (terminal).

npm run build

Builds the app for production under the build directory.
It correctly bundles React in production mode and optimizes the app for best performance.

The build is then minified and filenames include hashes.
By default, it also includes a service worker so that your app loads from local cache on future visits.

Your app is ready to be deployed.

npm test

Runs the test watcher in an interactive mode.
By default, this runs tests related to file changes since last commit.

Read more about testing.