The YARN installation is used to install all dependencies of a project. This is most commonly used when you have just checked out a project’s code or when another project developer has added a new dependency that you need to pick up.
If you’re used to using npm, you might expect to use -save or -save-dev. These have been replaced by yarn add and yarn add -dev. For more information, see the adding threads documentation.
Running yarn
without command will run yarn install, passing through any flag provided
. If you need
reproducible dependencies, which is usually the case with continuous integration systems, you need to pass the -frozen-lockfile flag
.
Installing yarn
Install all dependencies listed in package.json in the local node_modules folder. The yarn.lock file is
used as follows:
If yarn.lock is present and sufficient to satisfy
all the dependencies listed in package.json
- , the exact versions registered in yarn.lock are installed and yarn.lock will not change. Yarn will not be looking for newer versions.
- If yarn.lock is absent or not sufficient to satisfy all the dependencies listed in package.json (for example, if you manually add a dependency to package.json), Yarn searches for the latest available versions that satisfy the package.json constraints. The results are written to yarn.lock.
If you want to make sure that yarn.lock is not up to date, use -frozen-lockfile.
yarn install -check-files
Verify that files already installed on node_modules have not been removed
.
yarn install –
flat
Install all 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 you depend on across multiple version ranges. These will be added to your package.json in a resolutions field.
yarn install -force
This retrieves all packages, even those that were previously installed
.
yarn install -har
Generates an HTTP file of all network requests made during installation. HAR files are commonly used to investigate network performance and can be analyzed with tools like Google’s HAR Analyzer or HAR Viewer.
yarn install -ignore-scripts
Do not run any scripts defined in the project.json package 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
Do not read or generate a yarn.lock lock file. yarn
install – production
[=true|false]
Yarn
will not install any packages listed in devDependencies if the NODE_ENV environment variable is set to production. Use this indicator to instruct Yarn to ignore NODE_ENV and take your production status or not from this indicator instead.
Notes: -production is the same as -production=true. -prod is an alias for -production.
yarn install -pure-lockfile
Do not generate a yarn.lock lock file.
yarn install -focus
Shallow installs a package’s peer workspace dependencies under its node_modules folder. This allows you to run that workspace without creating the other workspaces you depend on.
It must run within an individual workspace in a workspace project. It cannot be run in a non-workspace project or in the root of a workspace project.
Learn more about focused workspaces.
yarn install -frozen-lockfile
Do not
generate a yarn.lock lock file and fail if an update is needed.
yarn install -silent Run the yarn installation without printing the installation log. yarn install -ignore-engines
Ignore engine checking
. yarn install -ignore-optional
Do not install optional dependencies
. yarn install -offline Run yarn install in
offline mode
. yarn install – non-interactive
Disable interactive
messages, such as when there is an invalid version of a dependency. yarn install –
update-checksums
Update the
checksums in the yarn.lock lock file if there is a mismatch between them and the checksum of your package.
yarn install -audit
Checks for known security issues with installed packages. A count of the issues found will be added to the output. Use the yarn audit command to learn more. Unlike npm, which automatically runs an audit on each installation, yarn will only do so when requested. (This may change in a later update, as the feature has been shown to be stable.)
yarn install -no-bin-links
Prevent yarn
from creating symbolic links for binary files that the package may contain
. yarn install -link-duplicates
Create hard links to repeated modules in node_modules.
yarn install -verbose
Show additional logs when installing dependencies