AutoFix-VisualStudioFiles.ps1 which formats and alphabetically organises elements in .config & .csproj files which commonly cause git merge conflicts

AutoFix-VisualStudioFiles.ps1

<#
.SYNOPSIS
 
    Scans the solution folder (the parent of the .git folder) for all app.config, web.config and *.csproj files 
    and auto-formats them to minimise the possibility of getting merge conflicts based on the ordering of 
    elements within these files.

    N.B. Use of this script is entirely at your own risk. We shall not be liable for any damage which may 
    result from using it.

.DESCRIPTION
    
    app.config & web.config files - sorts appSettings elements by key, in alphabetic order, sorts 
    assemblyBinding.dependentAssembly elements alphabetically based on the assemblyIdentity.name 
    attribute
    .csproj files - sorts appSettings elements by key, in alphabetic order, sorts Reference, 
    ProjectReference & Compile elements

.NOTES
    File Name  : AutoFix-VisualStudioFiles.ps1
    Author     : Howard van Rooijen (@HowardvRooijen)
    Requires   : PowerShell v3
.LINK

#>

Function AutoFix-WebConfig([string] $rootDirectory)
{
    $files = Get-ChildItem -Path $rootDirectory -Filter web.config -Recurse

    return Scan-ConfigFiles($files)
}

Function AutoFix-AppConfig([string] $rootDirectory)
{
    $files = Get-ChildItem -Path $rootDirectory -Filter app.config -Recurse

    return Scan-ConfigFiles($files)
}

Function Scan-ConfigFiles([System.IO.FileInfo[]] $files)
{
    $modifiedfiles = @()

    foreach($file in $files)
    {
        $original = [xml] (Get-Content $file.FullName)
        $workingCopy = $original.Clone()

        if ($workingCopy.configuration.appSettings -ne $null){
            $sorted = $workingCopy.configuration.appSettings.add | sort { [string]$_.key }
            $lastChild = $sorted[-1]
            $sorted[0..($sorted.Length-2)] | foreach {$workingCopy.configuration.appSettings.InsertBefore($_, $lastChild)} | Out-Null
        }

        if ($workingCopy.configuration.runtime.assemblyBinding -ne $null){
            $sorted = $workingCopy.configuration.runtime.assemblyBinding.dependentAssembly | sort { [string]$_.assemblyIdentity.name }
            $lastChild = $sorted[-1]
            $sorted[0..($sorted.Length-2)] | foreach {$workingCopy.configuration.runtime.assemblyBinding.InsertBefore($_,$lastChild)} | Out-Null
        }

        $differencesCount = (Compare-Object -ReferenceObject (Select-Xml -Xml $original -XPath "//*") -DifferenceObject (Select-Xml -Xml $workingCopy -XPath "//*")).Length

        if ($differencesCount -ne 0)
        {
            $workingCopy.Save($file.FullName) | Out-Null
            $modifiedfiles += $file.FullName
        }
    }

    return $modifiedfiles
}

Function AutoFix-CsProj([string] $rootDirectory)
{
    $files = Get-ChildItem -Path $rootDirectory -Filter *.csproj -Recurse
    $modifiedfiles = @()

    foreach($file in $files)
    {
        $original = [xml] (Get-Content $file.FullName)
        $workingCopy = $original.Clone()

        foreach($itemGroup in $workingCopy.Project.ItemGroup){

            # Sort the reference elements
            if ($itemGroup.Reference -ne $null){

                $sorted = $itemGroup.Reference | sort { [string]$_.Include }

                $itemGroup.RemoveAll() | Out-Null
 
                foreach($item in $sorted){
                    $itemGroup.AppendChild($item) | Out-Null
                }
            }

            # Sort the compile elements
            if ($itemGroup.Compile -ne $null){

                $sorted = $itemGroup.Compile | sort { [string]$_.Include }

                $itemGroup.RemoveAll() | Out-Null
 
                foreach($item in $sorted){
                    $itemGroup.AppendChild($item) | Out-Null
                }
            }

            # Sort the project references elements
            if ($itemGroup.ProjectReference -ne $null){

                $sorted = $itemGroup.ProjectReference | sort { [string]$_.Include }

                $itemGroup.RemoveAll() | Out-Null
 
                foreach($item in $sorted){
                    $itemGroup.AppendChild($item) | Out-Null
                }
            }
        }

        $differencesCount = (Compare-Object -ReferenceObject (Select-Xml -Xml $original -XPath "//*") -DifferenceObject (Select-Xml -Xml $workingCopy -XPath "//*")).Length

        if ($differencesCount -ne 0)
        {
            $workingCopy.Save($file.FullName) | Out-Null
            $modifiedfiles += $file.FullName
        }
    }

    return $modifiedfiles
}

$rootDirectory = Join-Path (Split-Path -Parent $MyInvocation.MyCommand.Path) "\..\..\"

$exitCode = 0;

$changedfiles = @()
$changedfiles += AutoFix-AppConfig($rootDirectory)
$changedfiles += AutoFix-CsProj($rootDirectory)
$changedfiles += AutoFix-WebConfig($rootDirectory)

if ($changedfiles.Count -gt 0)
{
    Write-Host "=== endjin git hooks ==="
    Write-Host "The following files have been auto-formatted"
    Write-Host "to reduce the likelyhood of merge conflicts:"
    
    foreach($file in $changedfiles)
    {
        Write-Host $file
    }

    $exitCode = 1;
}

exit $exitcode

Entries like this

-    <ProjectReference Include="..\Folder\Project.csproj">
-      <Project>{BC1989BA-C301-4BD3-BOB7-DI3D040F3A55}</Project>
-      <Name>Project</Name>
-    </ProjectReference>

gets removed after running this script.

I think this exception that is getting thrown is related, I never really needed to use powershell until now.
Don't really know how to debug it. (I'm going to try to fix it, but if u could help I'd appreciate ;x)

Exceção ao chamar "InsertBefore" com "2" argumento(s): "Referência de objeto não definida para uma instância de um
objeto."
No C:\workspace\Conecta\.git\hooks\AutoFix-VisualStudioFiles.ps1:53 caractere:55
+ ...  | foreach {$workingCopy.configuration.appSettings.InsertBefore($_, $ ...
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : DotNetMethodException

UPDATE:
Actually the exception seems to be about another thing.
I believe this lines shouldn't be there, right?
https://gist.github.com/HowardvanRooijen/a4c4c463e1c27b8857cb#file-autofix-visualstudiofiles-ps1-L91
https://gist.github.com/HowardvanRooijen/a4c4c463e1c27b8857cb#file-autofix-visualstudiofiles-ps1-L103
https://gist.github.com/HowardvanRooijen/a4c4c463e1c27b8857cb#file-autofix-visualstudiofiles-ps1-L115

UPDATE2:
I created a Fork and made a few changes to your script.
Seems to be working fine now. ;)