Use PowerShell to npm uninstall all packages

Recently I needed to delete all npm package folders which had been installed into the node_modules directory of a project. Attempting to manually delete the folders occasionally failed due to the maximum path length limitation Windows imposes. I didn't fancy running npm uninstall for each package individually as there were a lot of them, and knowing that I would likely need to repeat this task again I decided to try my hand at writing some PowerShell to uninstall each package listed in either the devDependencies section of package.json, or in the node_modules directory itself.

Uninstall packages, attempt one

First up I wrote a function which removes package folders added by a reference in devDependencies.

Function Uninstall-NpmPackagesInDevDependencies {
    Param (
        # Optional path to package.json
        [String]$pathToPackage= $(Resolve-Path "package.json")
    )

    # Read the json content
    $json = (Get-Content $pathToPackage -Raw) | ConvertFrom-Json

    # Loop over each package in devDependencies
    ForEach ($dep in ($json.devDependencies | Get-Member -MemberType *Property).Name) {
        # Uninstall the package
        iex "npm uninstall $dep"
    }
}

It works! However a few pesky folders still remained as they were saved in another section of the package.json.

Uninstall packages, attempt two

To deal with the leftover folders I created a second function which loops over all folders in the node_modules directory and uses the name of each folder to uninstall the package.

Function Uninstall-NpmPackagesInNodeModules {
    Param (
        # Optional path to node_modules directory
        [String]$pathToNodeModules = (Get-Item ".\node_modules").FullName
    )

    Get-ChildItem $pathToNodeModules | ForEach {
        # Uninstall the package
        iex "npm uninstall $($_.Name)"
    }
}

Trying out slightly different ForEach syntax for a bit of fun, I managed to remove all directories, regardless of whether the packages were saved in package.json or the path length was too long.

One liners

After some further searching online I came across a nice bash command for this sort of thing:

for package in `ls node_modules`; do npm uninstall $package; done;

Which led me to wonder what the equivilent would be if I shortened the Uninstall-NpmPackagesInDirectory function.

Stripping the function right back, and substituting method names for their shorter aliases resulted in

ls (gi ".\node_modules").FullName | % { iex "npm uninstall $($_.Name)" }

It doesn't read as well as the bash command, but I don't think it's too bad.

Just for the hell of it I thought I'd have a go at shortening the Uninstall-NpmPackagesInDevDependencies function as well, the result:

($(gc "package.json" -raw) | convertfrom-json).devdependencies | gm -membertype *property | % { iex "npm uninstall $dep" }

Not likely to remember that one off the top of my head the next time I need to use it..