npm jest cli code example

Example 1: jest command coverage

# in package.json
# "scripts": {
#     "test": "jest --coverage"
# },

# using yarn
yarn test

# using npm
npm run test

Example 2: testing with jest

npm i jest --save -dev
-> In Package.json change the Script object(watchAll - jest will run auto)
"test" : "jest --watchAll"
-> test file should be named such way that re used by jest can recognize it
like filename. or  or skip it.js
Ex: sum.test.js or sum.spec.js or sum.js
-> require the target for testing file in this test file then enjoy testing.
-> visit jestWebsite-> Docs.