Test if a file in a git repo is executable (i.e. has `chmod+x` set). Works on Windows as well as *nix systems.

Test-IsExecutable

# Thanks to Torek for the git command
# https://stackoverflow.com/questions/64607795/query-git-index-for-chmod-values-on-windows/64617017#64617017
# https://git-scm.com/docs/git-ls-files

function Test-IsExecutable {
    [CmdletBinding()]
    Param (
        # Side note: Not only should Path point to a file/files within a git repo
        # but also you should call this command from within that same repo
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [string[]]$Path
        ,
        [Parameter()]
        [Switch]$OutputBooleanOnly
    )
    Begin {
        [int]$mode = 0
    }
    Process {
        foreach ($file in $Path) {
            try {
                [string]$output = git ls-files --stage "$file"
                $result = [PSCustomObject]@{
                    FileName = $file
                    IsExecutable = [int]::TryParse(($output -replace '^(\d+).*', '$1'), [ref]$mode) -and ($mode -eq 100755)
                    Output = $output
                }
                if ($OutputBooleanOnly.IsPresent) {
                    $result.IsExecutable
                } else {
                    $result
                }
            } catch {
                write-error "$file - $($_.Exception.ToString())"
            }
        }
    }
}