[BUG] Empty policySetDefinitionId throws 'resourceId' null error in Azure.ResourceManager.PolicyInsights when loading PolicyStates

[lukerogers]

Library name and version

Azure.ResourceManager.PolicyInsights 1.0.0

Describe the bug

When loading the PolicyState for anything, if the "policySetDefinitionId" is null, it throws an error saying the resourceId is null. This field isn't required as a policy might not have a definition associated with it.

I believe the issue is that the type is a ResourceIdentifier and that object throws an error is the string is null or empty

Expected behavior

PolicyState is able to be loaded if policySetDefinitionId is empty

Actual behavior

System.ArgumentException: 'Value cannot be an empty string. (Parameter 'resourceId')' is thrown when the policySetDefinitionId is null.

In PolicyState.Serialization.cs (194), it passes an empty string to the contructor of the ResourceIdentifier object.

Here is the constructor for ResourceIdentifer

public ResourceIdentifier(string resourceId)
{
  Argument.AssertNotNullOrEmpty(resourceId, nameof(resourceId));

  _stringValue = resourceId;

  if (resourceId.Length == 1 && resourceId[0] == Separator)
  {
    //this is the same as Root but can't return that since this is a ctor
    Init(null, ResourceType.Tenant, string.Empty, false, SpecialType.None);
    return;
  }
}

I can't figure out what needs to change to made this work. Obviously a if(!string.IsNullOrEmpty(property.Value.GetString())) check in PolicyState.Serialization.cs before loading the ResourceIdentifier would work, but I don't know how to handle this with Autorest.

Reproduction Steps

Here is one of my payloads that is throwing the error with personal info removed:

{
  "@odata.id": null,
  "@odata.context": "https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroup}/providers/Microsoft.PolicyInsights/policyStates/$metadata#latest/$entity",
  "timestamp": "2022-10-06T03:15:53.8325601Z",
  "resourceId": "/subscriptions/{subscriptionId}/resourcegroups/{resourceGroup}/providers/microsoft.web/sites/{someSiteName}",
  "policyAssignmentId": "/providers/microsoft.management/managementgroups/{guid}/providers/microsoft.authorization/policyassignments/102",
  "policyDefinitionId": "/providers/microsoft.management/managementgroups/{guid}/providers/microsoft.authorization/policydefinitions/102",
  "effectiveParameters": "",
  "isCompliant": true,
  "subscriptionId": "{subscriptionId}",
  "resourceType": "Microsoft.Web/sites",
  "resourceLocation": "eastus2",
  "resourceGroup": "{resourceGroup}",
  "resourceTags": "tbd",
  "policyAssignmentName": "102",
  "policyAssignmentOwner": "tbd",
  "policyAssignmentParameters": "",
  "policyAssignmentScope": "/providers/Microsoft.Management/managementgroups/cfa5342f-a686-4a51-9d41-3736c6ba8c2e",
  "policyDefinitionName": "102",
  "policyDefinitionAction": "auditifnotexists",
  "policyDefinitionCategory": "tbd",
  "policySetDefinitionId": "",
  "policySetDefinitionName": "",
  "policySetDefinitionOwner": "",
  "policySetDefinitionCategory": "",
  "policySetDefinitionParameters": "",
  "managementGroupIds": "{guids}",
  "policyDefinitionReferenceId": "",
  "complianceState": "Compliant",
  "policyDefinitionGroupNames": [ "" ],
  "policyDefinitionVersion": "1.0.0",
  "policySetDefinitionVersion": "",
  "policyAssignmentVersion": "",
  "complianceReasonCode": ""
}

Try to deserialize that and it will throw the error.

Environment

I'm running this on Windows 11 with .NET version 6.0.9 and Visual Studio 2022

[jsquire]

Thank you for your feedback. Tagging and routing to the team member best able to assist.