The bower.json defines several options, one of those is the ignore option:
ignore [array]: An array of paths not needed in production that you want Bower to ignore when installing your package.
It is really important to use it when you are defining a bower.json of a package that is meant to be used from other apps or modules.
When a consumer installs your package via Bower, it will download your project’s entire git repository into their project. But in most of the cases, we don’t want to distribute everything. The consumer app doesn’t need things like tests, configuration files, tasks, etc. Only the original and minified versions of the component and the documentation. That will save time downloading the module and disk space.
The rule of thumb is to use the ignore attribute to define the list of files and directories that we don’t want to publish.