# skip-postinstall

A simple, cross-platform way to skip a postinstall script by setting an environment variable

## How?

Yarn:

```shell
yarn add --dev skip-postinstall
```

NPM:

```shell
npm install --save-dev skip-postinstall
```

Add `skip-postinstall || ` to your postinstall script:

```json
{
    "scripts": {
        "postinstall": "skip-postinstall || node-gyp rebuild"
    }
}
```

When you want to skip your postinstall script, simply set the `SKIP_POSTINSTALL` environment variable and run your command:

```shell
SKIP_POSTINSTALL=1 yarn install
```

## Why?

Currently, there is no built-in way to only skip a top-level postinstall in Yarn or NPM. You can use the `--ignore-scripts` option, but that will ignore the postinstall scripts in all of your dependencies as well. You can also try this approach, but it doesn't work on Windows:

```json
{
    "scripts": {
        "postinstall": "test -n \"$SKIP_POSTINSTALL\" || node-gyp rebuild"
    }
}
```

`skip-postinstall` allows you to do this in a way that works on macOS, Linux, and Windows without any other dependencies (just [one line](https://github.com/rajivshah3/skip-postinstall/blob/main/index.js#L3) of code!)


A simple, cross-platform way to skip a postinstall script by setting an environment variable. 

Meet the Socket Team at BlackHat and DEF CON in Las Vegas, Aug 4-6

skip-postinstall

A simple, cross-platform way to skip a postinstall script by setting an environment variable

rajivshah3

(Experimental) An ambiguous license classifier was found.

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Bad text encoding

Package version is not a valid semantic version (semver).

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Bad semver

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Bad dependency semver

Source files contain bidirectional unicode control characters. This could indicate a Trojan source supply chain attack. See: trojansource.codes for more information.

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Bidirectional unicode control characters

This package has multiple bin scripts with the same name. This can cause non-deterministic behavior when installing or could be a sign of a supply chain attack.

What is bin script confusion?

Bin script confusion

This Chrome extension includes a content script '{scriptFile}' that runs on websites matching '{matches}'.

What are Chrome extension content scripts?

Chrome Extension Content Script

This Chrome extension requests access to '{host}'.

What are Chrome extension host permissions?

Chrome Extension Host Permission

This Chrome extension uses the '{permission}' permission.

What are Chrome extension permissions?

Chrome Extension Permission

This Chrome extension requests broad access to websites with the pattern '{host}'.

What are Chrome extension wildcard host permissions?

Chrome Extension Wildcard Host Permission

Semantic versions published out of chronological order.

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Chronological version anomaly

Project maintainer's SSH key has been compromised.

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Compromised SSH key

(Experimental) Copyleft license information was found.

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Contains a Critical Common Vulnerability and Exposure (CVE).

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Title

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High CVE

Uses debug, reflection and dynamic code execution features.

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Debug access

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Deprecated

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Deprecated license

Package name is similar to other popular packages and may not be the package you want.

What is a typosquat?

Possible typosquat attack

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Dynamic require

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Empty package

Package accesses environment variables, which may be a sign of credential stuffing or data theft.

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Name

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File dependency

Accesses the file system, and could potentially read sensitive data.

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Filesystem access

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Wildcard dependency

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Git dependency

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GitHub dependency

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AI-detected possible typosquat

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AI-detected potential malware

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AI-detected potential security risk

Contains native code (e.g., compiled binaries or shared libraries). Including native code can obscure malicious behavior.

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Native code

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High entropy strings

Contains unicode homoglyphs which can be used in supply chain confusion attacks.

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Unicode homoglyphs

Contains a dependency which resolves to a remote HTTP URL which could be used to inject untrusted code and reduce overall package reliability.

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HTTP dependency

Install scripts are run when the package is installed. The majority of malware in npm is hidden in install scripts.

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Install scripts

Package has an invalid manifest file and can cause installation problems if you try to use it.

What is an invalid manifest file?

Invalid manifest file

Source files contain invisible characters. This could indicate source obfuscation or a supply chain attack.

What are invisible characters?

Invisible chars

(Experimental) Package license has recently changed.

What is a license change?

License change

(Experimental) Contains an SPDX license exception.

What is a license exception?

License exception

This package is not allowed per your license policy. Review the package's license to ensure compliance.

What is a license policy violation?

License Policy Violation

Contains long string literals, which may be a sign of obfuscated or packed code.

What's wrong with long strings?

Long strings

Package has recently undergone a major refactor. It may be unstable or indicate significant internal changes. Use caution when updating to versions that include significant changes.

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Major refactor

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Known malware

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Manifest confusion

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Medium CVE

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Low CVE

This package contains minified code. This may be harmless in some cases where minified code is included in packaged libraries, however packages on npm should not minify code.

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Minified code

(Experimental) A package's licensing information has fine-grained problems.

Misc. License Issues

The package was published by an npm account that no longer exists.

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Non-existent author

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Missing dependency

(Experimental) Package does not have a license and consumption legal status is unknown.

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Missing license

This package is missing its tarball. It could be removed from the npm registry or there may have been an error when publishing.

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Missing package tarball

(Experimental) Package contains multiple licenses.

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Mixed license

(Experimental) Package contains a modified version of an SPDX license exception. Please read carefully before using this code.

What is a modified license exception?

Modified license exception

(Experimental) Package contains a modified version of an SPDX license. Please read carefully before using this code.

What is a modified license?

Modified license

What is network access?

Network access

A new npm collaborator published a version of the package for the first time. New collaborators are usually benign additions to a project, but do indicate a change to the security surface area of a package.

What is new author?

New author

Package does not specify a list of contributors or an author in package.json.

Why is contributor and author data important?

No contributors or author data

Package does not have a linked bug tracker in package.json.

Why are bug trackers important?

No bug tracker

(Experimental) License information could not be found.

No License Found

Package does not have a README. This may indicate a failed publish or a low quality package.

Why are READMEs important?

No README

Package does not have a linked source code repository. Without this field, a package will have no reference to the location of the source code use to generate the package.

skip-postinstall

skip-postinstall

How?

Why?

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