yarn

yarn test [yarn test is also a shortcut for yarn run test.] yarn start yarn start-debug

view all the possible scripts in our package.json by execute yarn run

yarn run test-chrome
(npm run test-chrome)
yarn run lint-fix
yarn run prepush

You may define scripts in your package.json file.

{ "name": "my-package", "scripts": { "build": "babel src -d lib", "test": "jest" } }

yarn run [script] [-- ] #

If you have defined a scripts object in your package, this command will run the specified [script]. For example:

yarn run test

bug in some yarn versions

yarn –v
yarn config list
//yarn config set registry 'https://abc.com/artifactory/api/npm/npm/‘
//yarn config set '@types:registry' https://registry.npmjs.org/
//npm config delete registry

brew services list
// stop it
brew services stop cntlm
// then, open another window to start it manually so that you can see the output
cntlm –v
// brew services start cntlm

// something wrong in the cache?
rm -rf node_modules/
// still have cache?
yarn --force
yarn --verbose
// showed that you have cache in your home hidden library 
// in Terminal, paste the following, this will show all hidden files
defaults write com.apple.finder AppleShowAllFiles YES

// install the older version
npm install --global [email protected]