Kiota Client

[damianh]

What are you generating using Kiota, clients or plugins?

API Client/SDK

In what context or format are you using Kiota?

Windows executable

Client library/SDK language

Csharp

Describe the bug

I've using Kiota (version 1.19.1+d294e04ba7f756896878a7015df1648f9dc0bcde) to generate HubSpot clients from their OpenAPI catalog which contains ~85 separate specs. 4 of which failed with a stack overflow exception:

 at Kiota.Builder.Extensions.OpenApiSchemaExtensions.GetDiscriminatorPropertyName(Microsoft.OpenApi.Models.OpenApiSchema)
   at System.Linq.Enumerable+SelectListIterator`2[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Linq.Enumerable.TryGetFirst[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.Generic.IEnumerable`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>, Boolean ByRef)
   at System.Linq.Enumerable.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.Generic.IEnumerable`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at Kiota.Builder.Extensions.OpenApiSchemaExtensions.GetDiscriminatorPropertyName(Microsoft.OpenApi.Models.OpenApiSchema)
   at System.Linq.Enumerable+SelectListIterator`2[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Linq.Enumerable.TryGetFirst[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.Generic.IEnumerable`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>, Boolean ByRef)
   at System.Linq.Enumerable.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.Generic.IEnumerable`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   ... repeats

Expected behavior

Should generate a c# client.

How to reproduce

kiota generate --openapi https://api.hubspot.com/public/api/spec/v1/specs/Automation/Automation%20V4/versions/144908 --language csharp
kiota generate --openapi https://api.hubspot.com/public/api/spec/v1/specs/CRM/Exports/versions/95922 --language csharp
kiota generate --openapi https://api.hubspot.com/public/api/spec/v1/specs/Conversations/Conversations%20Inbox%20&%20Messages/versions/54902 --language csharp

Open API description file

https://api.hubspot.com/public/api/spec/v1/specs/Automation/Automation%20V4/versions/144908
https://api.hubspot.com/public/api/spec/v1/specs/CRM/Exports/versions/95922
https://api.hubspot.com/public/api/spec/v1/specs/Conversations/Conversations%20Inbox%20&%20Messages/versions/54902

Kiota Version

1.19.1+d294e04ba7f756896878a7015df1648f9dc0bcde

Latest Kiota version known to work for scenario above?(Not required)

No response

Known Workarounds

None

Configuration

• OS: Windows 11 x64.

Debug output

--debug flag didn't work.

Other information

No response

[andrueastman]

Thanks for raising this @damianh

--debug flag didn't work.

This looks to be related to the PR created at #5780. Any chance you can obtain a trace using --ll debug instead?

[andrueastman]

With the description from https://api.hubspot.com/public/api/spec/v1/specs/Automation/Automation%20V4/versions/144908

The stackoverflow seems to be caused by the method at

kiota/src/Kiota.Builder/Extensions/OpenApiSchemaExtensions.cs

Line 249 in 4c383b7

internal static string GetDiscriminatorPropertyName(this OpenApiSchema schema)

The description defines the schema below with two oneOfs.

      "ApiFlowCreateRequest" : {
        "properties" : { },
        "oneOf" : [ {
          "$ref" : "#/components/schemas/ApiContactFlowCreateRequest"
        }, {
          "$ref" : "#/components/schemas/ApiPlatformFlowCreateRequest"
        } ]
      },

However the referenced oneOfs end up referencing the same schema in the AllOf as

"ApiContactFlowCreateRequest" : {
        "properties" : { },
        "allOf" : [ {
          "$ref" : "#/components/schemas/ApiFlowCreateRequest"
        }, {
          "required" : [ "actions", "blockedDates", "canEnrollFromSalesforce", "customProperties", "flowType", "isEnabled", "objectTypeId", "suppressionListIds", "timeWindows", "type" ],
          "type" : "object",
          "properties" : {
            "type" : {
              "type" : "string",
              "default" : "CONTACT_FLOW",
              "enum" : [ "WORKFLOW", "ACTION_SET", "UNKNOWN" ]
            },
.....

So as the code recursively looks for the discriminator name from the base, the oneOfs end up referencing the base again in the allOf to end up in an infinite loop.

One thing I'm not sure if this is valid OpenApi or should Kiota detect the oneOfs in such a scenario as possible derived types(rather than trying to create a union type) given that what we ideally expect is an empty schema with a discriminator property name? cc @baywet