Some unfinished functions to handle CRUD in zip (/nupkg) archives.

FileInArchive.psm1

function Find-FileInArchive {
    <#
        .Synopsis
            Finds files matching a pattern in an archive.

        .Example
            Find-FileInArchive -Path "C:\Archive.zip" -like "tools/files/*-x86.exe"

        .Example
            Find-FileInArchive -Path $Nupkg -match "tools/files/dotnetcore-sdk-(?<Version>\d+\.\d+\.\d+)-win-x86\.exe(\.ignore)?"

        .Notes
            Please be aware that this matches against the full name of the file, not just the file name.
            Though given that, you can easily write something to match the file name.
    #>
    [CmdletBinding(DefaultParameterSetName="match")]
    param(
        # Path to the archive
        [Parameter(Mandatory)]
        [string]$Path,

        # Pattern to match with basic globbing
        [Parameter(Mandatory, ValueFromPipeline, ParameterSetName="match")]
        [string]$match,

        # Pattern to match with regex
        [Parameter(Mandatory, ParameterSetName="like")]
        [string]$like
    )
    begin {
        while (-not $Zip -and $AccessRetries++ -lt 3) {
            try {
                $Stream = [IO.FileStream]::new($Path, [IO.FileMode]::Open)
                $Zip = [IO.Compression.ZipArchive]::new($Stream, [IO.Compression.ZipArchiveMode]::Read)
            } catch [System.IO.IOException] {
                if ($AccessRetries -ge 3) {
                    Write-Error -Message "Accessing '$Path' failed after $AccessRetries attempts." -TargetObject $Path
                } else {
                    Write-Information "Could not access '$Path', retrying..."
                    Start-Sleep -Milliseconds 500
                }
            }
        }
    }
    process {
        if ($Zip) {
            $WhereBlock = [ScriptBlock]::Create("`$_.FullName -$($PSCmdlet.ParameterSetName) '$(Get-Variable -Name $PSCmdlet.ParameterSetName -ValueOnly)'")
            $Zip.Entries | Where-Object -FilterScript $WhereBlock
        }
    }
    end {
        if ($Zip) {
            $Zip.Dispose()
        }
        if ($Stream) {
            $Stream.Close()
            $Stream.Dispose()
        }
    }
}

function Remove-FileInArchive {
    <#
        .Synopsis
            Removes files from a zip formatted archive

        .Description
            In order to reduce the size of an archive, you may want to remove files from it.
            This function will remove the files you specify from the archive you specify.

        .Example
            Remove-FileInArchive -Path $Nupkg -Name dotnet-sdk-3.1.410-win-x86.exe dotnet-sdk-3.1.410-win-x86.exe.ignore

        .Example
            Remove-FileInArchive -Zip $Zip -FullName "tools/chocolateyInstall.ps1"
    #>
    [CmdletBinding(SupportsShouldProcess)]
    param(
        # Path to the archive
        [Parameter(Mandatory, ParameterSetName = "PathFullName")]
        [Parameter(Mandatory, ParameterSetName = "PathName")]
        [string]$Path,

        # Zip object for the archive
        [Parameter(Mandatory, ParameterSetName = "ZipFullName")]
        [Parameter(Mandatory, ParameterSetName = "ZipName")]
        [IO.Compression.ZipArchive]$Zip,

        # Name of the file(s) to remove in the archive
        [Parameter(Mandatory, ValueFromPipeline, ValueFromRemainingArguments, ParameterSetName="PathFullName")]
        [Parameter(Mandatory, ValueFromPipeline, ValueFromRemainingArguments, ParameterSetName="ZipFullName")]
        [string[]]$FullName,

        # Name of the file(s) to remove in the archive
        [Parameter(Mandatory, ValueFromPipeline, ValueFromRemainingArguments, ParameterSetName="PathName")]
        [Parameter(Mandatory, ValueFromPipeline, ValueFromRemainingArguments, ParameterSetName="ZipName")]
        [string[]]$Name
    )
    begin {
        if (-not $PSCmdlet.ParameterSetName.StartsWith("Zip")) {
            $Stream = [IO.FileStream]::new($Path, [IO.FileMode]::Open)
            $Zip = [IO.Compression.ZipArchive]::new($Stream, [IO.Compression.ZipArchiveMode]::Update)
        }
    }
    process {
        foreach ($File in Get-Variable -Name $PSCmdlet.ParameterSetName.TrimStart('PathZip') -ValueOnly) {
            ($Zip.Entries | Where-Object {$_."$($PSCmdlet.ParameterSetName.TrimStart('PathZip'))" -eq $File}) | ForEach-Object {
                if ($PSCmdlet.ShouldProcess($_.FullName, "Remove")) {
                    $_.Delete()
                }
            }
        }
    }
    end {
        if (-not $PSCmdlet.ParameterSetName.StartsWith("Zip")) {
            $Zip.Dispose()
            $Stream.Close()
            $Stream.Dispose()
        }
    }
}

function Get-FileContentInArchive {
    <#
        .Synopsis
            Returns the content of a file from within an archive

        .Example
            Get-FileContentInArchive -Path $ZipPath -Name "chocolateyInstall.ps1"

        .Example
            Get-FileContentInArchive -Zip $Zip -FullName "tools\chocolateyInstall.ps1"
    #>
    [CmdletBinding(DefaultParameterSetName="PathFullName")]
    [OutputType([string])]
    param(
        # Path to the archive
        [Parameter(Mandatory, ParameterSetName = "PathFullName")]
        [Parameter(Mandatory, ParameterSetName = "PathName")]
        [string]$Path,

        # Zip object for the archive
        [Parameter(Mandatory, ParameterSetName = "ZipFullName")]
        [Parameter(Mandatory, ParameterSetName = "ZipName")]
        [IO.Compression.ZipArchive]$Zip,

        # Name of the file(s) to remove from the archive
        [Parameter(Mandatory, ParameterSetName = "PathFullName")]
        [Parameter(Mandatory, ParameterSetName = "ZipFullName")]
        [string]$FullName,

        # Name of the file(s) to remove from the archive
        [Parameter(Mandatory, ParameterSetName = "PathName")]
        [Parameter(Mandatory, ParameterSetName = "ZipName")]
        [string]$Name
    )
    begin {
        if (-not $PSCmdlet.ParameterSetName.StartsWith("Zip")) {
            $Stream = [IO.FileStream]::new($Path, [IO.FileMode]::Open)
            $Zip = [IO.Compression.ZipArchive]::new($Stream, [IO.Compression.ZipArchiveMode]::Read)
        }
    }
    process {
        if (-not $FullName) {
            $MatchingEntries = $Zip.Entries | Where-Object {$_.Name -eq $Name}
            if ($MatchingEntries.Count -ne 1) {
                Write-Error "File '$Name' not found in archive" -ErrorAction Stop
            }
            $FullName = $MatchingEntries[0].FullName
        }
        [System.IO.StreamReader]::new(
            $Zip.GetEntry($FullName).Open()
        ).ReadToEnd()
    }
    end {
        if (-not $PSCmdlet.ParameterSetName.StartsWith("Zip")) {
            $Zip.Dispose()
            $Stream.Close()
            $Stream.Dispose()
        }
    }
}

function Update-FileInArchive {
    <#
        .Synopsis
            Updates a text file in an archive

        .Description
            In order to remove references to given files from install scripts, you may want to update a file within an archive (without repacking it).
            This function will update the content of files in the archive you specify.

        .Example
            Update-FileInArchive -Path $Nupkg -FullName "tools/chocolateyInstall.ps1" -Value $UpdatedScript

        .Example
            Update-FileInArchive -Zip $Zip -Name "chocolateyInstall.ps1" -Value $UpdatedScript
    #>
    [CmdletBinding(DefaultParameterSetName="PathFullName", SupportsShouldProcess)]
    param(
        # Path to the archive
        [Parameter(Mandatory, ParameterSetName = "PathFullName")]
        [Parameter(Mandatory, ParameterSetName = "PathName")]
        [string]$Path,

        # Zip object for the archive
        [Parameter(Mandatory, ParameterSetName = "ZipFullName")]
        [Parameter(Mandatory, ParameterSetName = "ZipName")]
        [IO.Compression.ZipArchive]$Zip,

        # Name of the file to update in the archive
        [Parameter(Mandatory, ParameterSetName = "PathFullName")]
        [Parameter(Mandatory, ParameterSetName = "ZipFullName")]
        [string]$FullName,

        # Name of the file to update in the archive
        [Parameter(Mandatory, ParameterSetName = "PathName")]
        [Parameter(Mandatory, ParameterSetName = "ZipName")]
        [string]$Name,

        # Value to set the file to
        [Parameter(Mandatory)]
        [string]$Value
    )
    begin {
        if (-not $PSCmdlet.ParameterSetName.StartsWith("Zip")) {
            $Stream = [IO.FileStream]::new($Path, [IO.FileMode]::Open)
            $Zip = [IO.Compression.ZipArchive]::new($Stream, [IO.Compression.ZipArchiveMode]::Update)
        }
    }
    process {
        if (-not $FullName) {
            $MatchingEntries = $Zip.Entries | Where-Object {$_.Name -eq $Name}
            if ($MatchingEntries.Count -ne 1) {
                Write-Error "File '$Name' not found in archive" -ErrorAction Stop
            }
            $FullName = $MatchingEntries[0].FullName
        }
        if ($PSCmdlet.ShouldProcess("Update", $_.FullName)) {
            # Either remove file, create entry
            Remove-FileInArchive -Zip $Zip -FullName $FullName
            $Zip.CreateEntry()

            # Or update existing entry and length

        }
    }
    end {
        if (-not $PSCmdlet.ParameterSetName.StartsWith("Zip")) {
            $Zip.Dispose()
            $Stream.Close()
            $Stream.Dispose()
        }
    }
}