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Description

Identifies packages that are installed multiple times in node_modules. Can optimize storage by creating symlinks between duplicate packages, reducing disk space usage.

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Usage

rev-dep node-modules installed-duplicates [flags]

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Examples

# Find duplicate packages
rev-dep node-modules installed-duplicates

# Automatically optimize duplicates with size statistics
rev-dep node-modules installed-duplicates --optimize --size-stats

# Optimize with verbose output
rev-dep node-modules installed-duplicates --optimize --verbose

# Isolate symlinks within top-level directories
rev-dep node-modules installed-duplicates --optimize --isolate

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Flags

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-c, --cwd
string
default:"$PWD"
Working directory for the command
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-h, --help
boolean
Help for installed-duplicates
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--isolate
boolean
Create symlinks only within the same top-level node_module directories. By default, optimize creates symlinks between top-level node_module directories (e.g. when workspaces are used). Needs --optimize flag to take effect
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--optimize
boolean
Automatically create symlinks to deduplicate packages
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--size-stats
boolean
Print node modules dirs size before and after optimization. Might take longer than optimization itself
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--verbose
boolean
Show detailed information about each optimization

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Use Cases

Disk Space Optimization

Reduce disk space usage by deduplicating identical package installations.

Monorepo Optimization

Deduplicate packages across workspace packages by creating symlinks between top-level node_modules directories.

Workspace Isolation

Use --isolate to keep symlinks within each workspace’s node_modules for stricter isolation.
Always test your application after optimization. While symlinks are generally safe, some tools may not handle them correctly.
Use --size-stats to see exactly how much disk space you’re saving. This can help justify the optimization step.

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How It Works

The command identifies packages with identical content (same name and version) installed in multiple locations. When --optimize is used, it:
  1. Finds all duplicate package installations
  2. Keeps one copy of each duplicate
  3. Replaces other copies with symlinks to the kept copy
  4. Optionally displays size savings with --size-stats

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Isolation Modes

Creates symlinks between top-level node_modules directories. Maximizes disk space savings in monorepos with workspaces.
rev-dep node-modules installed-duplicates --optimize

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