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

.TH "NPM\-CI" "1" "May 2021" "" ""
.SH "NAME"
\fBnpm-ci\fR \- Install a project with a clean slate
.SS Synopsis
.P
.RS 2
.nf
npm ci
.fi
.RE
.SS Description
.P
This command is similar to npm help \fBinstall\fP, 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\.
.P
\fBnpm ci\fP will be significantly faster when:
.RS 0
.IP \(bu 2
There is a \fBpackage\-lock\.json\fP or \fBnpm\-shrinkwrap\.json\fP file\.
.IP \(bu 2
The \fBnode_modules\fP folder is missing or empty\.

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

.RE