Yarn deduplicate
Cleans up yarn.lock
by removing duplicates.
A duplicate package is when two dependencies are resolved to a different version, even when a single
version will sufice to match the range specified in the dependencies. See the section 'Deduplication
strategies' for a few examples.
Installation
Install the package globally:
npm install -g yarn-deduplicate
or
yarn global add yarn-deduplicate
This package also works wth npx,
so you don't need to install it.
Usage
The most common scenario is to run
yarn-deduplicate yarn.lock
This will use the default strategy to remove duplicated packages in yarn.lock
.
Check all available options with:
yarn-deduplicate --help
Duplicated packages
yarn.lock
contains a list of all the dependencies required by your project (including transitive
dependencies), and the actual package version installed to satistfy those dependencies.
For the context of this project, a "duplicated package" is a package that appers on multiple nodes
of the dependency tree with overlapping version ranges but resolved to different versions.
For example, imagine that your project directly depends on lodash
and babel
, and babel
depends
on lodash
as well. Specifically, your project depends on lodash@^1.0.0
and babel
depends on
lodash@^1.1.0
. Because how the resolution algorithm works in Yarn, you might end up with two
different copies of lodash
(for example, version 1.0.1
and 1.2.0
) in your project, even when
1.2.0
will sufice to satisfy both requirements for lodash
. That's a "duplicated package".
It is important to note that we do not consider duplicated packages when the version ranges don't
overlap. For example, if your project depends on underscore@^1.0.0
and underscore@^2.0.0
. Your
project will end up with two versions of underscore
, and yarn-tools
won't change that.
When using yarn-deduplicate
remember that it will change your dependency tree. There are
certain code paths that now will run with a different set of dependencies. It is highly recommended
that you review each change to yarn.lock
. If the change is too big, use the flag --packages
to
deduplicate them gradually.
Deduplication strategies
highest
It will try to use the highest installed version. For example, with the following yarn.lock
:
library@^1.1.0:
version "1.2.0"
library@^1.2.0:
version "1.2.0"
library@^1.3.0:
version "1.3.0"
It will deduplicate library@^1.1.0
and library@^1.2.0
to 1.3.0
fewer
It will try to minimize the number of installed versions by trying to deduplicate to the version
that satisfies most of the ranges first. For example, with the following yarn.lock
:
library@*:
version "2.0.0"
library@>=1.1.0:
version "3.0.0"
library@^1.2.0:
version "1.2.0"
It will deduplicate library@*
and library@>=1.1.0
to 1.2.0
.
Note that this will cause some packages to downgrade it version. Be sure to check the changelogs
between all versions and understand the consequences of that downgrade. If unsure, don't use this
strategy.
It is not recommended to use different strategies for different packages. There is no guarantee that
the strategy will be honored in subsequent runs of yarn-deduplicate
unless the same set of flags
is specified again.
Progressive deduplication
--packages <package1> <package2> <packageN>
Receives a list of packages to deduplicate. It will ignore any other duplicated package not in the
list. This option is recommended when the number of duplicated packages in yarn.lock
is too big
to be easily reviewed by a human. This will allow for a more controlled and progressive
deduplication of yarn.lock
.
Migration guide
From 0.x to 1.x
In this version we have renamed the project and refactored the CLI. These are the equivalent
commands:
Installation
npm install -g yarn-tools
npm install -g yarn-deduplicate
List duplicates
yarn-tools list-duplicates path/to/yarn.lock
yarn-deduplicate --list path/to/yarn.lock
Deduplicate yarn.lock
yarn-tools fix-duplicates path/to/yarn.lock > tmp
mv tmp path/to/yarn.lock
yarn-deduplicate path/to/yarn.lock
Limit packages to deduplicate yarn.lock
yarn-tools fix-duplicates path/to/yarn.lock package1 package2
yarn-deduplicate --packages package1,package2 path/to/yarn.lock
Contributors
Pull requests, issues and comments welcome. For pull requests:
- Add tests for new features and bug fixes
- Follow the existing style
- Separate unrelated changes into multiple pull requests
See the existing issues for things to start contributing.
For bigger changes, make sure you start a discussion first by creating
an issue and explaining the intended change.
Atlassian requires contributors to sign a Contributor License Agreement,
known as a CLA. This serves as a record stating that the contributor is
entitled to contribute the code/documentation/translation to the project
and is willing to have it used in distributions and derivative works
(or is willing to transfer ownership).
Prior to accepting your contributions we ask that you please follow the appropriate
link below to digitally sign the CLA. The Corporate CLA is for those who are
contributing as a member of an organization and the individual CLA is for
those contributing as an individual.
License
Copyright (c) 2017 Atlassian and others.
Apache 2.0 licensed, see LICENSE.txt file.