About
A dev dependency is a build and test dependency.
They
- are not needed in the dependency graph (bundler, test harnesses or transpilers)
- will not be downloaded when an other package uses your package as a dependency.
Management
Add
This command will modify the devependency properties of package.json
cd DirectoryOfPackage.Json
# then
yarn add [package] --dev
# or
npm install packageName --save-dev