example .travis .yml file

learned from udemy

sudo: required
#above says we need to have superuser-level permission to make this working
services:
  - docker
#above says we need the docker cli installed so it will install a copy of docker into the running container

before_install :
  - docker build -t kishlayraj2/docker-react -f Dockerfile.dev .
  #above says what needs to happen before we deploy our project or run our test

script :
  # will tell how to run the test suite
  # if from any of the below commands it gets any return code other than 0 then its going to assume that the process has failed

  - docker run kishlayraj2/docker-react npm run test -- --coverage
  #the only problem here is that "npm run test" wait for input from the user and doesn't terminate itself automatically, and to make it stop automatically we will use -- --coverage