Discriminator information for parent types used in properties

[andrueastman]

Taking a look at the graph metadata for beta , there exists the userSet type which is abstract.

<ComplexType Name="userSet" Abstract="true">
  <Property Name="isBackup" Type="Edm.Boolean" />
</ComplexType>

It also has several other derived types (such as externalSponsors, groupMembers, internalSponsors) as shown below.

<ComplexType Name="externalSponsors" BaseType="graph.userSet" />
<ComplexType Name="groupMembers" BaseType="graph.userSet">
  <Property Name="description" Type="Edm.String" />
  <Property Name="id" Type="Edm.String" />
</ComplexType>
<ComplexType Name="internalSponsors" BaseType="graph.userSet" />
<ComplexType Name="logicAppTriggerEndpointConfiguration" BaseType="graph.customExtensionEndpointConfiguration">
  <Property Name="logicAppWorkflowName" Type="Edm.String" />
  <Property Name="resourceGroupName" Type="Edm.String" />
  <Property Name="subscriptionId" Type="Edm.String" />
</ComplexType>

The abstract userSet type is referenced through properties of other classes as shown below

<ComplexType Name="approvalStage">
  <Property Name="approvalStageTimeOutInDays" Type="Edm.Int32" />
  <Property Name="escalationApprovers" Type="Collection(graph.userSet)" />   -----> SEE HERE
  <Property Name="escalationTimeInMinutes" Type="Edm.Int32" />
  <Property Name="isApproverJustificationRequired" Type="Edm.Boolean" />
  <Property Name="isEscalationEnabled" Type="Edm.Boolean" />
  <Property Name="primaryApprovers" Type="Collection(graph.userSet)" />   -----> SEE HERE
</ComplexType>
<ComplexType Name="assignmentReviewSettings">
  <Property Name="accessReviewTimeoutBehavior" Type="graph.accessReviewTimeoutBehavior" />
  <Property Name="durationInDays" Type="Edm.Int32" />
  <Property Name="isAccessRecommendationEnabled" Type="Edm.Boolean" />
  <Property Name="isApprovalJustificationRequired" Type="Edm.Boolean" />
  <Property Name="isEnabled" Type="Edm.Boolean" />
  <Property Name="recurrenceType" Type="Edm.String" />
  <Property Name="reviewers" Type="Collection(graph.userSet)" />          -----> SEE HERE
  <Property Name="reviewerType" Type="Edm.String" />
  <Property Name="startDateTime" Type="Edm.DateTimeOffset" />
</ComplexType>

The generated OpenAPI description.

    microsoft.graph.userSet:
      title: userSet
      type: object
      properties:
        isBackup:
          type: boolean
          description: 'For a user in an approval stage, this property indicates whether the user is a backup fallback approver.'
          nullable: true

Question
Should the userSet type have the appropriate discriminator mappings for the derived types? Or is this only limited to types used in nav properties?
The current situation leads to Kiota failing to generate the derived type models of the userSet class.

cc @baywet, @irvinesunday , @darrelmiller

[baywet]

Thanks for reporting this!
The fact that a type is exposed through a navigation property or a "regular" property doesn't change the inheritance structure.
An approval stage could perfectly come back with a group members entry in the escalation approvers property. In that case the service should annotate the odata type at that level to help the client deserialize to the correct target type. And the client should know what to do with it.
So yes, even in that specific case, the conversion library should add that information to the component.

[andrueastman]

Thanks for clarifying on this one @baywet