ParameterArgumentTransformationError

Question

I have a script, see below, that searches for the most recent MSDeploy executable on the sys drive.

However, my Compare-FileVersion function is not called due to the following error:

Compare-FileVersions : Cannot process argument transformation on parameter 'file1'. Cannot convert the "System.Object[]" value of type "System.Object[]" to type "System.IO.FileInfo". At C:\DATA\Git\PowerShell\Test-Command.ps1:32 char:39
+         $winner = Compare-FileVersions($incumbent, $challenger);
+                                       ~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidData: (:) [Compare-FileVersions], ParameterBindingArgumentTransformationException
    + FullyQualifiedErrorId : ParameterArgumentTransformationError,Compare-FileVersions

Here's the script:

function Find-Executable()
{
    # Find all MS Deploy executables and then make a table of path and version. Reverse sort and pick top one.

    pushd;

    # Workaround for bug in PS where ErrorAction spec'ed in the argument is ignored. http://stackoverflow.com/questions/17489372/ls-recurse-erroraction-silentlycontinue-doesnt-work

    # Bug is not fixed on build server with this code.

    $originalEAP = $ErrorActionPreference;
    $ErrorActionPreference = "SilentlyContinue";

    cd $env:SystemDrive;
    cd \;
    [System.IO.FileInfo[]]$allExecutables = ls -Include msdeploy.exe -Recurse -Force -ErrorAction SilentlyContinue;

    $ErrorActionPreference = $originalEAP;

    popd;

    if ($allExecutables.Count -lt 1)
    {
        throw $("No MS Deploy executables found in folders in " + $env:SystemDrive);
    }    

    [System.IO.FileInfo]$incumbent = $allExecutables[0];
    for($i = 0; $i -lt $allExecutables.Count; $i++)
    {        
        [System.IO.FileInfo]$challenger = $allExecutables[$i];
        $winner = Compare-FileVersions($incumbent, $challenger);
        $incumbent = $winner;
    }

    return $winner;
}

function Compare-FileVersions([System.IO.FileInfo]$file1, [System.IO.FileInfo]$file2)
{
    if ($file1.VersionInfo.FileMajorPart -gt $file2.VersionInfo.FileMajorPart)
    {
        return $file1;
    }
    elseif ($file2.VersionInfo.FileMajorPart -gt $file1.VersionInfo.FileMajorPart)
    {
        return $file2;
    }

    if ($file1.VersionInfo.FileMinorPart -gt $file2.VersionInfo.FileMinorPart)
    {
        return $file1;
    }
    elseif ($file2.VersionInfo.FileMinorPart -gt $file1.VersionInfo.FileMinorPart)
    {
        return $file2;
    }

    if ($file1.VersionInfo.FileBuildPart -gt $file2.VersionInfo.FileBuildPart)
    {
        return $file1;
    }
    elseif ($file2.VersionInfo.FileBuildPart -gt $file1.VersionInfo.FileBuildPart)
    {
        return $file2;
    }

    if ($file1.VersionInfo.FilePrivatePart -gt $file2.VersionInfo.FilePrivatePart)
    {
        return $file1;
    }
    elseif ($file2.VersionInfo.FilePrivatePart -gt $file1.VersionInfo.FilePrivatePart)
    {
        return $file2;
    }

    # They're both the same at this point.

    return $file1;
}

$version = Find-Executable;

echo $version;

But here's proof that the types of the variables being passed as parameters are indeed correct (clearly they're not, somehow, else I wouldn't be here on SO):

They're both FileInfo, the arguments are both of that type. So what am I missing?

Answer 1

You will get this error if you pass arguments like this

$winner = Compare-FileVersions($incumbent,$challenger)

try to separate these two variable with a space like this and it will work.

$winner = (Compare-FileVersions $incumbent $challenger)