npm-dedupe

Synopsis

npmdedupe

alias: 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 [email protected]
|`-- [email protected]
`-- d<-- depends on c@~1.0.9
`-- [email protected]

In this case,npm dedupewill transform the tree to:

a
+-- b
+-- d
`-- [email protected]

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 [email protected]
+-- [email protected]
`-- d<-- depends on [email protected]
`-- [email protected]

During the installation process, the[email protected]dependency forbwas placed in the root of the tree. Thoughd's dependency on[email protected]could have been satisfied by[email protected],the newer[email protected]dependency was used, because npm favors updates by default, even when doing so causes duplication.

Runningnpm dedupewill cause npm to note the duplication and re-evaluate, deleting the nestedcmodule, because the one in the root is sufficient.

To prefer deduplication over novelty during the installation process, runnpm install --prefer-dedupeornpm 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.

Usingnpm find-dupeswill run the command in--dry-runmode.

Note:npm dedupewill never update the semver values of direct dependencies in your projectpackage.json,if you want to update values inpackage.jsonyou can run:npm update --saveinstead.

Configuration

install-strategy

• Default: "hoisted"
• Type: "hoisted", "nested", "shallow", or "linked"

Sets the strategy for installing packages in node_modules. hoisted (default): Install non-duplicated in top-level, and duplicated as necessary within directory structure. nested: (formerly --legacy-bundling) install in place, no hoisting. shallow (formerly --global-style) only install direct deps at top-level. linked: (experimental) install in node_modules/.store, link in place, unhoisted.

legacy-bundling

• Default: false
• Type: Boolean
• DEPRECATED: This option has been deprecated in favor of--install-strategy=nested

Instead of hoisting package installs innode_modules,install packages in the same manner that they are depended on. This may cause very deep directory structures and duplicate package installs as there is no de-duplicating. Sets--install-strategy=nested.

global-style

• Default: false
• Type: Boolean
• DEPRECATED: This option has been deprecated in favor of--install-strategy=shallow

Only install direct dependencies in the top levelnode_modules,but hoist on deeper dependencies. Sets--install-strategy=shallow.

strict-peer-deps

• Default: false
• Type: Boolean

If set totrue,and--legacy-peer-depsis not set, thenanyconflictingpeerDependencieswill be treated as an install failure, even if npm could reasonably guess the appropriate resolution based on non-peer dependency relationships.

By default, conflictingpeerDependenciesdeep 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'speerDependenciesobject.

When such an override is performed, a warning is printed, explaining the conflict and the packages involved. If--strict-peer-depsis set, then this warning is treated as a failure.

package-lock

• Default: true
• Type: Boolean

If set to false, then ignorepackage-lock.jsonfiles when installing. This will also preventwritingpackage-lock.jsonifsaveis true.

omit

• Default: 'dev' if theNODE_ENVenvironment 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 dependenciesarestill resolved and added to thepackage-lock.jsonornpm-shrinkwrap.jsonfile. They are just not physically installed on disk.

If a package type appears in both the--includeand--omitlists, then it will be included.

If the resulting omit list includes'dev',then theNODE_ENVenvironment variable will be set to'production'for all lifecycle scripts.

include

• Default:
• Type: "prod", "dev", "optional", or "peer" (can be set multiple times)

Option that allows for defining which types of dependencies to install.

This is the inverse of--omit=<type>.

Dependency types specified in--includewill not be omitted, regardless of the order in which omit/include are specified on the command-line.

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 asnpm start,npm stop,npm restart,npm test,andnpm run-scriptwill still run their intended script ifignore-scriptsis set, but they willnotrun 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 fornpm auditfor details on what is submitted.

bin-links

• Default: true
• Type: Boolean

Tells npm to create symlinks (or.cmdshims 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 eachnpm installacknowledging the number of dependencies looking for funding. Seenpm fundfor 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 aspackandpublish.

Note: This is NOT honored by other network related commands, egdist-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 theworkspaceconfig are either:

• Workspace names
• Path to a workspace directory
• Path to a parent workspace directory (will result in selecting all workspaces within that folder)

When set for thenpm initcommand, 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: null
• Type: null or Boolean

Set to true to run the command in the context ofallconfigured workspaces.

Explicitly setting this to false will cause commands likeinstallto ignore workspaces altogether. When not set explicitly:

• Commands that operate on thenode_modulestree (install, update, etc.) will link workspaces into thenode_modulesfolder. - Commands that do other things (test, exec, publish, etc.) will operate on the root project,unlessone or more workspaces are specified in theworkspaceconfig.

This value is not exported to the environment for child processes.

include-workspace-root

• Default: false
• Type: Boolean

Include the workspace root when workspaces are enabled for a command.

When false, specifying individual workspaces via theworkspaceconfig, or all workspaces via theworkspacesflag, will cause npm to operate only on the specified workspaces, and not on the root project.

This value is not exported to the environment for child processes.

install-links

• Default: false
• Type: Boolean

When set file: protocol dependencies will be packed and installed as regular dependencies instead of creating a symlink. This option has no effect on workspaces.

See Also

• npm find-dupes
• npm ls
• npm update
• npm install

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Last edited bylukekarrysonOctober 5, 2022