How do I run selenium after serving create react app application? - selenium

Question

I am trying to make some e2e tests with selenium over my Create React App application.
The problem is that before selenium can even run, I must run the react application itself (using for example npm start).
The problem: serving the app will stay in 'watch' mode in any autumation process I am trying to build.
Is it possible to run a create react app, and only after that selenium? (using grunt, npm or whatever?)
The current flow:
Run react development server with grunt (using npm start)
Run selenium
Is there a way to make them work one after the other?
grunfile:
require('dotenv').config();
module.exports = function(grunt) {
const API = process.env.REACT_APP_API_PATH + ':' + process.env.REACT_APP_API_PORT + '/api';
const DEV_PORT = 3001;
grunt.initConfig({
http: {
prepare_e2e_tests: {
options: {
url: API + '/prepare_e2e_tests'
}
}
},
exec: {
start_dev_server: {
cmd: 'REACT_APP_IS_TESTING=true PORT=' + DEV_PORT + ' npm start'
},
e2e: {
cmd: 'DEV_SERVER_PORT=3001 npm run e2e'
}
},
concurrent: {
test: {
tasks: ['http:prepare_e2e_tests','exec:start_dev_server','exec:e2e'],
options: {
logConcurrentOutput: true
}
}
}
});
grunt.registerTask('run_e2e', function() {
console.log('running e2e tests');
grutn.task.run('exec:e2e')
});
grunt.registerTask('prepare_server', function() {
console.log('preparing e2e tests on server:');
grunt.task.run('http:prepare_e2e_tests');
});
grunt.registerTask('setup_dev_server', function() {
console.log('running development server on port ' + DEV_PORT);
grunt.task.run('exec:start_dev_server');
});
grunt.registerTask('test', 'run e2e tests', ['concurrent:test']);
grunt.loadNpmTasks('grunt-http');
grunt.loadNpmTasks('grunt-exec');
grunt.loadNpmTasks('grunt-concurrent');
grunt.registerTask('default', []);
};
Thanks!