npm-ci
Install a project with a clean slateTable of contents
Synopsis
npm ci
Example
Make sure you have a package-lock and an up-to-date install:
$ cd ./my/npm/project
$ npm install
added 154 packages in 10s
$ ls | grep package-lock
Run npm ci in that project
$ npm ci
added 154 packages in 5s
Configure Travis to build using npm ci instead of npm install:
# .travis.yml
install:
- npm ci
# keep the npm cache around to speed up installs
cache:
directories:
- "$HOME/.npm"
Description
This command is similar to npm install, except it’s meant to be used in
automated environments such as test platforms, continuous integration, and
deployment – or any situation where you want to make sure you’re doing a clean
install of your dependencies. It can be significantly faster than a regular npm
install by skipping certain user-oriented features. It is also more strict than
a regular install, which can help catch errors or inconsistencies caused by the
incrementally-installed local environments of most npm users.
In short, the main differences between using npm install and npm ci are:
- The project must have an existing
package-lock.jsonornpm-shrinkwrap.json. - If dependencies in the package lock do not match those in
package.json,npm ciwill exit with an error, instead of updating the package lock. npm cican only install entire projects at a time: individual dependencies cannot be added with this command.- If a
node_modulesis already present, it will be automatically removed beforenpm cibegins its install. - It will never write to
package.jsonor any of the package-locks: installs are essentially frozen.