param(
    [Parameter(Mandatory)]
    $oldFeatures,
    [Parameter(Mandatory)]
    $newFeatures
)

$result = @()

foreach ($newFeature in $newFeatures) {
    $oldFeature = $oldFeatures |
        Where-Object Name -eq $newFeature.Name

    if (-not $oldFeature) {
        $result += [pscustomobject]@{
            ChangeType = 'Added'
            Name       = $newFeature.Name
            DisplayName = $newFeature.DisplayName
            OldValue   = $null
            NewValue   = $newFeature.InstallState
        }
        continue
    }

    if ($oldFeature.InstallState -ne $newFeature.InstallState) {
        $result += [pscustomobject]@{
            ChangeType = 'Changed'
            Name       = $newFeature.Name
            DisplayName = $newFeature.DisplayName
            OldValue   = $oldFeature.InstallState
            NewValue   = $newFeature.InstallState
        }
    }
}

foreach ($oldFeature in $oldFeatures) {
    if ($oldFeature.Name -notin $newFeatures.Name) {
        $result += [pscustomobject]@{
            ChangeType = 'Removed'
            Name       = $oldFeature.Name
            DisplayName = $oldFeature.DisplayName
            OldValue   = $oldFeature.InstallState
            NewValue   = $null
        }
    }
}

$result