functions/accessReviews/Test-TmfAccessReview.ps1

function Test-TmfAccessReview
{
    <#
        .SYNOPSIS
            Test desired configuration against a Tenant.
        .DESCRIPTION
            Compare current configuration of a resource type with the desired configuration.
            Return a result object with the required changes and actions.
    #>

    [CmdletBinding()]
    Param (
        [System.Management.Automation.PSCmdlet]
        $Cmdlet = $PSCmdlet
    )
    
    begin
    {
        Test-GraphConnection -Cmdlet $Cmdlet
        $resourceName = "accessReviews"
        $tenant = Get-MgOrganization -Property displayName, Id
    }
    process
    {
        foreach ($definition in $script:desiredConfiguration[$resourceName]) {
            foreach ($property in $definition.Properties()) {
                if ($definition.$property.GetType().Name -eq "String") {
                    $definition.$property = Resolve-String -Text $definition.$property
                }
            }

            $result = @{
                Tenant = $tenant.displayName
                TenantId = $tenant.Id
                ResourceType = 'AccessReview'
                ResourceName = (Resolve-String -Text $definition.displayName)
                DesiredConfiguration = $definition
            }
            
            try {
                $resource = (Invoke-MgGraphRequest -Method GET -Uri ("$script:graphBaseUrl/identityGovernance/accessReviews/definitions/?`$filter=displayName eq '{0}'" -f [System.Web.HttpUtility]::UrlEncode($definition.displayName))).Value
            }
            catch {
                Write-PSFMessage -Level Warning -String 'TMF.Error.QueryWithFilterFailed' -StringValues $filter -Tag 'failed'
                $exception = New-Object System.Data.DataException("Query with filter $filter against Microsoft Graph failed. Error: $_")
                $errorID = 'QueryWithFilterFailed'
                $category = [System.Management.Automation.ErrorCategory]::NotSpecified
                $recordObject = New-Object System.Management.Automation.ErrorRecord($exception, $errorID, $category, $Cmdlet)
                $cmdlet.ThrowTerminatingError($recordObject)
            }
            
            switch ($resource.Count) {
                0 {
                    if ($definition.present) {                    
                        if ((Get-Date -Date ($definition.settings.recurrence.range.startDate)) -lt (Get-Date -Format "yyyy-MM-dd")) {
                            Write-PSFMessage -Level Warning -String 'TMF.Error.StartDateValidationFailed' -StringValues $filter -Tag 'failed'
                            $exception = New-Object System.Data.DataException("$($result.ResourceType) ($($result.ResourceName)) can not be created with parameter startDate in the past!")
                            $errorID = "StartDateValidationFailed"
                            $category = [System.Management.Automation.ErrorCategory]::NotSpecified
                            $recordObject = New-Object System.Management.Automation.ErrorRecord($exception, $errorID, $category, $Cmdlet)
                            $cmdlet.ThrowTerminatingError($recordObject)
                        }
                        $result = New-TestResult @result -ActionType "Create"
                    }
                    else {                    
                        $result = New-TestResult @result -ActionType "NoActionRequired"
                    }
                }
                1 {
                    $result["GraphResource"] = $resource
                    if ($definition.present) {
                        $changes = @()
                        foreach ($property in ($definition.Properties() | Where-Object {$_ -notin "displayName", "present"})) {
                            $change = [PSCustomObject] @{
                                Property = $property                                        
                                Actions = $null
                            }
                            
                            switch ($property) {
                                "settings" {
                                    foreach ($item in ($definition.$property.GetEnumerator().Name | Where-Object {$_ -notin "applyActions","recurrence"})) {
                                        if (($definition.$property.$item -ne $resource.$property.$item) -and $definition.$property.$item.gettype()) {
                                            $change.Actions = @{"Set" = $definition.$property.$item}
                                        }
                                    }
                                    foreach ($item in $definition.$property.recurrence.pattern.GetEnumerator().Name) {
                                        if ($definition.$property.recurrence.pattern.$item -ne $resource.$property.recurrence.pattern.$item){
                                            $change.Actions = @{"Set" = $definition.$property.recurrence.pattern}
                                        }
                                    }
                                    foreach ($item in $definition.$property.recurrence.range.GetEnumerator().Name) {
                                        if ($definition.$property.recurrence.range.$item -ne $resource.$property.recurrence.range.$item){
                                            $change.Actions = @{"Set" = $definition.$property.recurrence.range}
                                        }
                                    }
                                }
                                "reviewers" {
                                    if (Compare-Object $definition.$property.query $resource.$property.query) {
                                        $change.Actions = @{"Set" = $definition.$property}
                                    }
                                }
                                "scope" {
                                    if ($definition.$property.query) {
                                        if ($resource.$property.query) {
                                            if (Compare-Object $definition.$property.query $resource.$property.query) {

                                                Write-PSFMessage -Level Warning -String 'TMF.Error.ScopeValidationFailed' -StringValues $filter -Tag 'failed'
                                                $exception = New-Object System.Data.DataException("$($result.ResourceType) ($($result.ResourceName)): Scope for existing access review can not be changed!")
                                                $errorID = "ScopeValidationFailed"
                                                $category = [System.Management.Automation.ErrorCategory]::NotSpecified
                                                $recordObject = New-Object System.Management.Automation.ErrorRecord($exception, $errorID, $category, $Cmdlet)
                                                $cmdlet.ThrowTerminatingError($recordObject)
                                            }
                                        }
                                        else {
                                            Write-PSFMessage -Level Warning -String 'TMF.Error.ScopeValidationFailed' -StringValues $filter -Tag 'failed'
                                            $exception = New-Object System.Data.DataException("$($result.ResourceType) ($($result.ResourceName)): Scope for existing access review can not be changed!")
                                            $errorID = "ScopeValidationFailed"
                                            $category = [System.Management.Automation.ErrorCategory]::NotSpecified
                                            $recordObject = New-Object System.Management.Automation.ErrorRecord($exception, $errorID, $category, $Cmdlet)
                                            $cmdlet.ThrowTerminatingError($recordObject)
                                        }
                                    }
                                    else {
                                        if ($definition.$property.principalScopes) {
                                            if (Compare-Object $definition.$property.principalScopes.query $resource.$property.principalScopes.query) {
                                                Write-PSFMessage -Level Warning -String 'TMF.Error.ScopeValidationFailed' -StringValues $filter -Tag 'failed'
                                                $exception = New-Object System.Data.DataException("$($result.ResourceType) ($($result.ResourceName)): Scope for existing access review can not be changed!")
                                                $errorID = "ScopeValidationFailed"
                                                $category = [System.Management.Automation.ErrorCategory]::NotSpecified
                                                $recordObject = New-Object System.Management.Automation.ErrorRecord($exception, $errorID, $category, $Cmdlet)
                                                $cmdlet.ThrowTerminatingError($recordObject)
                                            }
                                        }
                                    }
                                }
                            }

                            if ($change.Actions) {$changes += $change}
                        }
                        
                        if ($changes.count -gt 0) { $result = New-TestResult @result -Changes $changes -ActionType "Update"}
                        else { $result = New-TestResult @result -ActionType "NoActionRequired" }
                    }
                    else {
                        $result = New-TestResult @result -ActionType "Delete"
                    }
                }
                default {
                    Write-PSFMessage -Level Warning -String 'TMF.Test.MultipleResourcesError' -StringValues $resourceName, $definition.displayName -Tag 'failed'
                    $exception = New-Object System.Data.DataException("Query returned multiple results. Cannot decide which resource to test.")
                    $errorID = 'MultipleResourcesError'
                    $category = [System.Management.Automation.ErrorCategory]::NotSpecified
                    $recordObject = New-Object System.Management.Automation.ErrorRecord($exception, $errorID, $category, $Cmdlet)
                    $cmdlet.ThrowTerminatingError($recordObject)
                }
            }
            
            $result
        }
    }
}