Compare-Directory.ps1

[CmdletBinding(DefaultParameterSetName = "default")]
param (
    [Parameter(Mandatory = $true, Position = 0)]
    [Parameter(ParameterSetName = "default")]
    [alias("l")]
    [string] $LeftPath,

    [Parameter(Mandatory = $true, Position = 1)]
    [Parameter(ParameterSetName = "default")]
    [alias("r")]
    [string] $RightPath,

    [Parameter(ParameterSetName = "default")]
    [switch] $Force,

    [Parameter(ParameterSetName = "File")]
    [switch] $File,

    [Parameter(ParameterSetName = "Directory")]
    [switch] $Directory
)

function Get-Hash([string] $Path, [string] $Algorithm = "MD5") {
    (Get-FileHash -LiteralPath $Path -Algorithm $Algorithm).Hash
}

function Get-Items([string] $Path) {
    Get-ChildItem -LiteralPath $Path -Recurse -Force:$Force -File:$File -Directory:$Directory
}

function Get-ItemsWithHash([string] $Path) {
    try {
        Push-Location $Path

        Get-Items $Path | Select-Object ("FullName", "Length",
            @{n = "RelativePath"; e = { Resolve-Path $_.FullName -Relative } },
            @{n = "Hash"; e = { Get-Hash $_.FullName } })
    }
    finally {
        Pop-Location
    }
}

function Compare-Directory {
    [CmdletBinding()]
    param (
        [parameter(Mandatory = $true, Position = 0)]
        [alias("l")]
        [string] $LeftPath,

        [parameter(Mandatory = $true, Position = 1)]
        [alias("r")]
        [string] $RightPath
    )

    $LeftHash = Get-ItemsWithHash $LeftPath
    $RightHash = Get-ItemsWithHash $RightPath
    Compare-Object -ReferenceObject $LeftHash -DifferenceObject $RightHash -Property "RelativePath", "Hash"
}

filter Find-LeftSide { $_ | ? { $_.SideIndicator -eq "<=" } }
filter Find-RightSide { $_ | ? { $_.SideIndicator -eq "=>" } }
filter Select-RelativePath { $_ | Select-Object -ExpandProperty "RelativePath" }

$LeftHash = Get-ItemsWithHash $LeftPath
$RightHash = Get-ItemsWithHash $RightPath

Write-Host "ディレクトリ配下の全てのファイルの差分を表示"
[PSCustomObject]@{
    "Side" = "Left"
    "TotalCount" = $LeftHash.Count
    "Directory"  = Resolve-Path -LiteralPath $LeftPath
},
[PSCustomObject]@{
    "Side" = "Right"
    "TotalCount" = $RightHash.Count
    "Directory"  = Resolve-Path -LiteralPath $RightPath
} | Format-Table -AutoSize

$diff = Compare-Object -ReferenceObject $LeftHash -DifferenceObject $RightHash -Property "RelativePath", "Hash"

$leftDiff = $diff | Find-LeftSide
$rightDiff = $diff | Find-RightSide

$diff2 = Compare-Object @($leftDiff) @($rightDiff) -Property "RelativePath"
$leftOnly = $diff2 | Find-LeftSide | Select-RelativePath
$rightOnly = $diff2 | Find-RightSide | Select-RelativePath
$diffOnly = $diff | Select-RelativePath | Group-Object -CaseSensitive | ? { $_.Count -ge 2 } | Select-Object -ExpandProperty Name

Write-Host "`n`tDiff:`t$($diffOnly.Count)"
$diffOnly

Write-Host "`n`tLeft:`t$($leftOnly.Count)"
$leftOnly

Write-Host "`n`tRight:`t$($rightOnly.Count)"
$rightOnly