npm-dedupe
Reduce duplication in the package treeTable of contents
Synopsis
npm dedupe
npm ddp
aliases: ddp
Description
Searches the local package tree and attempts to simplify the overall structure by moving dependencies further up the tree, where they can be more effectively shared by multiple dependent packages.
For example, consider this dependency graph:
a
+-- b <-- depends on c@1.0.x
| `-- c@1.0.3
`-- d <-- depends on c@~1.0.9
`-- c@1.0.10
In this case, npm dedupe
will transform the tree to:
a
+-- b
+-- d
`-- c@1.0.10
Because of the hierarchical nature of node’s module lookup, b and d will both get their dependency met by the single c package at the root level of the tree.
In some cases, you may have a dependency graph like this:
a
+-- b <-- depends on c@1.0.x
+-- c@1.0.3
`-- d <-- depends on c@1.x
`-- c@1.9.9
During the installation process, the c@1.0.3
dependency for b
was
placed in the root of the tree. Though d
’s dependency on c@1.x
could
have been satisfied by c@1.0.3
, the newer c@1.9.0
dependency was used,
because npm favors updates by default, even when doing so causes
duplication.
Running npm dedupe
will cause npm to note the duplication and
re-evaluate, deleting the nested c
module, because the one in the root is
sufficient.
To prefer deduplication over novelty during the installation process, run
npm install --prefer-dedupe
or npm config set prefer-dedupe true
.
Arguments are ignored. Dedupe always acts on the entire tree.
Note that this operation transforms the dependency tree, but will never result in new modules being installed.
Using npm find-dupes
will run the command in --dry-run
mode.
Configuration
global-style
- Default: false
- Type: Boolean
Causes npm to install the package into your local node_modules
folder with
the same layout it uses with the global node_modules
folder. Only your
direct dependencies will show in node_modules
and everything they depend
on will be flattened in their node_modules
folders. This obviously will
eliminate some deduping. If used with legacy-bundling
, legacy-bundling
will be preferred.
legacy-bundling
- Default: false
- Type: Boolean
Causes npm to install the package such that versions of npm prior to 1.4,
such as the one included with node 0.8, can install the package. This
eliminates all automatic deduping. If used with global-style
this option
will be preferred.
strict-peer-deps
- Default: false
- Type: Boolean
If set to true
, and --legacy-peer-deps
is not set, then any
conflicting peerDependencies
will be treated as an install failure, even
if npm could reasonably guess the appropriate resolution based on non-peer
dependency relationships.
By default, conflicting peerDependencies
deep in the dependency graph will
be resolved using the nearest non-peer dependency specification, even if
doing so will result in some packages receiving a peer dependency outside
the range set in their package’s peerDependencies
object.
When such and override is performed, a warning is printed, explaining the
conflict and the packages involved. If --strict-peer-deps
is set, then
this warning is treated as a failure.
package-lock
- Default: true
- Type: Boolean
If set to false, then ignore package-lock.json
files when installing. This
will also prevent writing package-lock.json
if save
is true.
When package package-locks are disabled, automatic pruning of extraneous
modules will also be disabled. To remove extraneous modules with
package-locks disabled use npm prune
.
omit
- Default: ‘dev’ if the
NODE_ENV
environment variable is set to ‘production’, otherwise empty. - Type: “dev”, “optional”, or “peer” (can be set multiple times)
Dependency types to omit from the installation tree on disk.
Note that these dependencies are still resolved and added to the
package-lock.json
or npm-shrinkwrap.json
file. They are just not
physically installed on disk.
If a package type appears in both the --include
and --omit
lists, then
it will be included.
If the resulting omit list includes 'dev'
, then the NODE_ENV
environment
variable will be set to 'production'
for all lifecycle scripts.
ignore-scripts
- Default: false
- Type: Boolean
If true, npm does not run scripts specified in package.json files.
Note that commands explicitly intended to run a particular script, such as
npm start
, npm stop
, npm restart
, npm test
, and npm run-script
will still run their intended script if ignore-scripts
is set, but they
will not run any pre- or post-scripts.
audit
- Default: true
- Type: Boolean
When “true” submit audit reports alongside the current npm command to the
default registry and all registries configured for scopes. See the
documentation for npm audit
for details on what is
submitted.
bin-links
- Default: true
- Type: Boolean
Tells npm to create symlinks (or .cmd
shims on Windows) for package
executables.
Set to false to have it not do this. This can be used to work around the fact that some file systems don’t support symlinks, even on ostensibly Unix systems.
fund
- Default: true
- Type: Boolean
When “true” displays the message at the end of each npm install
acknowledging the number of dependencies looking for funding. See npm fund
for details.
dry-run
- Default: false
- Type: Boolean
Indicates that you don’t want npm to make any changes and that it should
only report what it would have done. This can be passed into any of the
commands that modify your local installation, eg, install
, update
,
dedupe
, uninstall
, as well as pack
and publish
.
Note: This is NOT honored by other network related commands, eg dist-tags
,
owner
, etc.
workspace
- Default:
- Type: String (can be set multiple times)
Enable running a command in the context of the configured workspaces of the current project while filtering by running only the workspaces defined by this configuration option.
Valid values for the workspace
config are either:
- Workspace names
- Path to a workspace directory
- Path to a parent workspace directory (will result to selecting all of the nested workspaces)
When set for the npm init
command, this may be set to the folder of a
workspace which does not yet exist, to create the folder and set it up as a
brand new workspace within the project.
This value is not exported to the environment for child processes.
workspaces
- Default: false
- Type: Boolean
Enable running a command in the context of all the configured workspaces.
This value is not exported to the environment for child processes.