nodejs/deps/npm/man/man1/npm-ci.1

.TH "NPM\-CI" "" "November 2019" "" ""
.SH "NAME"
\fBnpm-ci\fR
.SH Install a project with a clean slate
.SS Synopsis
.P
.RS 2
.nf
npm ci
.fi
.RE
.SS Example
.P
Make sure you have a package\-lock and an up\-to\-date install:
.P
.RS 2
.nf
$ cd \./my/npm/project
$ npm install
added 154 packages in 10s
$ ls | grep package\-lock
.fi
.RE
.P
Run \fBnpm ci\fP in that project
.P
.RS 2
.nf
$ npm ci
added 154 packages in 5s
.fi
.RE
.P
Configure Travis to build using \fBnpm ci\fP instead of \fBnpm install\fP:
.P
.RS 2
.nf
# \.travis\.yml
install:
\- npm ci
# keep the npm cache around to speed up installs
cache:
  directories:
  \- "$HOME/\.npm"
.fi
.RE
.SS Description
.P
This command is similar to \fBnpm\-install\fP \fInpm\-install\fR, 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\.
.P
In short, the main differences between using \fBnpm install\fP and \fBnpm ci\fP are:
.RS 0
.IP \(bu 2
The project \fBmust\fR have an existing \fBpackage\-lock\.json\fP or \fBnpm\-shrinkwrap\.json\fP\|\.
.IP \(bu 2
If dependencies in the package lock do not match those in \fBpackage\.json\fP, \fBnpm ci\fP will exit with an error, instead of updating the package lock\.
.IP \(bu 2
\fBnpm ci\fP can only install entire projects at a time: individual dependencies cannot be added with this command\.
.IP \(bu 2
If a \fBnode_modules\fP is already present, it will be automatically removed before \fBnpm ci\fP begins its install\.
.IP \(bu 2
It will never write to \fBpackage\.json\fP or any of the package\-locks: installs are essentially frozen\.

.RE
.SS See Also
.RS 0
.IP \(bu 2
npm help npm\-install
.IP \(bu 2
npm help package\-locks

.RE