yarn install
yarn install
is used to install all dependencies for a project. This is most
commonly used when you have just checked out code for a project, or when
another developer on the project has added a new dependency that you need to
pick up.
If you are used to using npm you might be expecting to use --save
or
--save-dev
. These have been replaced by yarn add
and yarn add --dev
. For
more information, see
the yarn add
documentation.
Running yarn
with no command will run yarn install
, passing through any provided flags.
If you need reproducible dependencies, which is usually the case with the continuous integration systems, you should pass --frozen-lockfile
flag.
yarn install
Install all the dependencies listed within package.json
in the local
node_modules
folder.
The yarn.lock
file is utilized as follows:
- If
yarn.lock
is present and is enough to satisfy all the dependencies listed inpackage.json
, the exact versions recorded inyarn.lock
are installed, andyarn.lock
will be unchanged. Yarn will not check for newer versions. - If
yarn.lock
is absent, or is not enough to satisfy all the dependencies listed inpackage.json
(for example, if you manually add a dependency topackage.json
), Yarn looks for the newest versions available that satisfy the constraints inpackage.json
. The results are written toyarn.lock
.
If you want to ensure yarn.lock
is not updated, use --frozen-lockfile
.
yarn install --check-files
Verifies that already installed files in node_modules
did not get removed.
yarn install --flat
Install all the dependencies, but only allow one version for each package. On the first run this will prompt you to
choose a single version for each package that is depended on at multiple
version ranges. These will be added to your package.json
under a
resolutions
field.
"resolutions": {
"package-a": "2.0.0",
"package-b": "5.0.0",
"package-c": "1.5.2"
}
yarn install --force
This refetches all packages, even ones that were previously installed.
yarn install --har
Outputs an HTTP archive from all the network requests performed during the installation. HAR files are commonly used to investigate network performance, and can be analyzed with tools such as Google’s HAR Analyzer or HAR Viewer.
yarn install --ignore-scripts
Do not execute any scripts defined in the project package.json and its dependencies.
yarn install --modules-folder <path>
Specifies an alternate location for the node_modules
directory, instead of the default ./node_modules
.
yarn install --no-lockfile
Don’t read or generate a yarn.lock
lockfile.
yarn install --production[=true|false]
Yarn will not install any package listed in devDependencies
if the NODE_ENV
environment variable is set to production
. Use this flag to instruct Yarn to ignore NODE_ENV
and take its production-or-not status from this flag instead.
Notes:
--production
is the same as--production=true
.--prod
is an alias of--production
.
yarn install --pure-lockfile
Don’t generate a yarn.lock
lockfile.
yarn install --focus
Shallowly installs a package’s sibling workspace dependencies underneath its node_modules
folder. This allows you to run that workspace without building the other workspaces it depends on.
Must be run inside an individual workspace in a workspaces project. Can not be run in a non-workspaces project or at the root of a workspaces project.
Learn more about focused workspaces.
yarn install --frozen-lockfile
Don’t generate a yarn.lock
lockfile and fail if an update is needed.
yarn install --silent
Run yarn install without printing installation log.
yarn install --ignore-engines
Ignore engines check.
yarn install --ignore-optional
Don’t install optional dependencies.
yarn install --offline
Run yarn install in offline mode.
yarn install --non-interactive
Disable interactive prompts, like when there’s an invalid version of a dependency.
yarn install --update-checksums
Update checksums in the yarn.lock
lockfile if there’s a mismatch between them and their package’s checksum.
yarn install --audit
Checks for known security issues with the installed packages. A count of found issues will be added to the output. Use the yarn audit
command for additional details. Unlike npm, which automatically runs an audit on every install, yarn will only do so when requested. (This may change in a later update as the feature is proven to be stable.)
yarn install --no-bin-links
Prevent yarn from creating symlinks for any binaries the package might contain.
yarn install --link-duplicates
Create hardlinks to the repeated modules in node_modules.
yarn install --verbose
Show additional logs while installing dependencies