[Schema Inaccuracy] Server fails to send 'slug' and 'name' fields for InstallationAccount, but in the generated code they're mandatory.

The affected schema is components.schemas.enterprise.required, reached through the /app/installations response and its installation account union. Start by checking the GHES 3.12 OpenAPI input at the listed remoteInputSpec, then verify the generated model/InstallationAccount.kt no longer requires name and slug. Done means appsListInstallations can deserialize the response without MissingFieldException.

Schema Inaccuracy

Server fails to send 'slug' and 'name' fields for model/InstallationAccount.kt, but in the generated code they're mandatory.

Expected

Fields 'slug' and 'name' for InstallationAccount should be optional, according to the server response, but not the Kotlin generated code.

These seem to need changing:
components.schemas.enterprise.required - remove (name, slug)

paths./app/installations.responses.200 refers to components/schemas/installation which has a union:

          "account": {
            "nullable": true,
            "anyOf": [
              {
                "$ref": "#/components/schemas/simple-user"
              },
              {
                "$ref": "#/components/schemas/enterprise"
              }
            ]
          },

Reproduction Steps

I'm calling AppsApi().appsListInstallations() and getting an exception from my Enterprise server: GitHub Enterprise Server 3.12.8

Caused by: kotlinx.serialization.MissingFieldException: Fields [name, slug] are required for type with serial name 'com.bumble.sdlc.github.model.InstallationAccount', but they were missing

I've looked at the response json, and they are indeed missing.

If I add ? to make them nullable, this particular issue is fixed.

remoteInputSpec = "https://raw.githubusercontent.com/github/rest-api-description/refs/heads/main/descriptions/ghes-3.12/ghes-3.12.json"

openapi-generator/.config:
{
    "library": "jvm-ktor",
    "dateLibrary": "java8",
    "serializationLibrary": "kotlinx_serialization",
    "enumPropertyNaming": "UPPERCASE",
    "omitGradleWrapper": "true",
    "omitGradlePluginVersions": "true"
}

Exception in thread "main" io.ktor.serialization.JsonConvertException: Illegal input: Fields [name, slug] are required for type with serial name 'com.bumble.sdlc.github.model.InstallationAccount', but they were missing at path: $[0].account
	at io.ktor.serialization.kotlinx.KotlinxSerializationConverter.deserialize(KotlinxSerializationConverter.kt:77)
	at io.ktor.serialization.ContentConverterKt$deserialize$$inlined$map$1$2.emit(Emitters.kt:51)
	at kotlinx.coroutines.flow.FlowKt__BuildersKt$asFlow$$inlined$unsafeFlow$3.collect(SafeCollector.common.kt:111)
	at io.ktor.serialization.ContentConverterKt$deserialize$$inlined$map$1.collect(SafeCollector.common.kt:109)
	at kotlinx.coroutines.flow.FlowKt__ReduceKt.firstOrNull(Reduce.kt:247)
	at kotlinx.coroutines.flow.FlowKt.firstOrNull(Unknown Source)
	at io.ktor.serialization.ContentConverterKt.deserialize(ContentConverter.kt:99)
	at io.ktor.client.plugins.contentnegotiation.ContentNegotiationKt.ContentNegotiation$lambda$13$convertResponse(ContentNegotiation.kt:234)
	at io.ktor.client.plugins.contentnegotiation.ContentNegotiationKt.access$ContentNegotiation$lambda$13$convertResponse(ContentNegotiation.kt:1)
	at io.ktor.client.plugins.contentnegotiation.ContentNegotiationKt$ContentNegotiation$2$2.invokeSuspend(ContentNegotiation.kt:249)
	at io.ktor.client.plugins.contentnegotiation.ContentNegotiationKt$ContentNegotiation$2$2.invoke(ContentNegotiation.kt)
	at io.ktor.client.plugins.contentnegotiation.ContentNegotiationKt$ContentNegotiation$2$2.invoke(ContentNegotiation.kt)
	at io.ktor.client.plugins.api.TransformResponseBodyHook$install$1.invokeSuspend(KtorCallContexts.kt:105)
	at io.ktor.client.plugins.api.TransformResponseBodyHook$install$1.invoke(KtorCallContexts.kt)
	at io.ktor.client.plugins.api.TransformResponseBodyHook$install$1.invoke(KtorCallContexts.kt)
	at io.ktor.util.pipeline.DebugPipelineContext.proceedLoop(DebugPipelineContext.kt:79)
	at io.ktor.util.pipeline.DebugPipelineContext.proceed(DebugPipelineContext.kt:57)
	at io.ktor.client.HttpClient$4.invokeSuspend(HttpClient.kt:1379)
	at io.ktor.client.HttpClient$4.invoke(HttpClient.kt)
	at io.ktor.client.HttpClient$4.invoke(HttpClient.kt)
	at io.ktor.util.pipeline.DebugPipelineContext.proceedLoop(DebugPipelineContext.kt:79)
	at io.ktor.util.pipeline.DebugPipelineContext.proceed(DebugPipelineContext.kt:57)
	at io.ktor.client.plugins.logging.ReceiveHook$Context.proceed(Logging.kt:290)
	at io.ktor.client.plugins.logging.LoggingKt$Logging$2$3.invokeSuspend(Logging.kt:209)
	at io.ktor.client.plugins.logging.LoggingKt$Logging$2$3.invoke(Logging.kt)
	at io.ktor.client.plugins.logging.LoggingKt$Logging$2$3.invoke(Logging.kt)
	at io.ktor.client.plugins.logging.ReceiveHook$install$1.invokeSuspend(Logging.kt:298)
	at io.ktor.client.plugins.logging.ReceiveHook$install$1.invoke(Logging.kt)
	at io.ktor.client.plugins.logging.ReceiveHook$install$1.invoke(Logging.kt)
	at io.ktor.util.pipeline.DebugPipelineContext.proceedLoop(DebugPipelineContext.kt:79)
	at io.ktor.util.pipeline.DebugPipelineContext.proceed(DebugPipelineContext.kt:57)
	at io.ktor.client.plugins.ReceiveError$install$1.invokeSuspend(HttpCallValidator.kt:149)
	at io.ktor.client.plugins.ReceiveError$install$1.invoke(HttpCallValidator.kt)
	at io.ktor.client.plugins.ReceiveError$install$1.invoke(HttpCallValidator.kt)
	at io.ktor.util.pipeline.DebugPipelineContext.proceedLoop(DebugPipelineContext.kt:79)
	at io.ktor.util.pipeline.DebugPipelineContext.proceed(DebugPipelineContext.kt:57)
	at io.ktor.util.pipeline.DebugPipelineContext.execute$ktor_utils(DebugPipelineContext.kt:63)
	at io.ktor.util.pipeline.Pipeline.execute(Pipeline.kt:79)
	at io.ktor.client.call.HttpClientCall.bodyNullable(HttpClientCall.kt:86)
	at com.bumble.sdlc.github.api.AppsApi.appsListInstallations(AppsApi.kt:1014)
	at com.bumble.sdlc.github.api.AppsApi$appsListInstallations$1.invokeSuspend(AppsApi.kt)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:100)
	at kotlinx.coroutines.EventLoopImplBase.processNextEvent(EventLoop.common.kt:263)
	at kotlinx.coroutines.BlockingCoroutine.joinBlocking(Builders.kt:95)
	at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking(Builders.kt:69)
	at kotlinx.coroutines.BuildersKt.runBlocking(Unknown Source)
	at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking$default(Builders.kt:47)
	at kotlinx.coroutines.BuildersKt.runBlocking$default(Unknown Source)
	at com.bumble.sdlc.github.client.GitHubMultiClientKt.main(GitHubMultiClient.kt:80)
	at com.bumble.sdlc.github.client.GitHubMultiClientKt.main(GitHubMultiClient.kt)
Caused by: kotlinx.serialization.MissingFieldException: Fields [name, slug] are required for type with serial name 'com.bumble.sdlc.github.model.InstallationAccount', but they were missing at path: $[0].account
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:95)
	at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableValue(AbstractDecoder.kt:43)
	at kotlinx.serialization.encoding.AbstractDecoder.decodeNullableSerializableElement(AbstractDecoder.kt:78)
	at com.bumble.sdlc.github.model.Installation$$serializer.deserialize(Installation.kt:35)
	at com.bumble.sdlc.github.model.Installation$$serializer.deserialize(Installation.kt:35)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:69)
	at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableValue(AbstractDecoder.kt:43)
	at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableElement(AbstractDecoder.kt:70)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableElement(StreamingJsonDecoder.kt:168)
	at kotlinx.serialization.encoding.CompositeDecoder$DefaultImpls.decodeSerializableElement$default(Decoding.kt:538)
	at kotlinx.serialization.internal.CollectionLikeSerializer.readElement(CollectionSerializers.kt:80)
	at kotlinx.serialization.internal.AbstractCollectionSerializer.readElement$default(CollectionSerializers.kt:51)
	at kotlinx.serialization.internal.AbstractCollectionSerializer.merge(CollectionSerializers.kt:36)
	at kotlinx.serialization.internal.AbstractCollectionSerializer.deserialize(CollectionSerializers.kt:43)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:69)
	at kotlinx.serialization.json.Json.decodeFromString(Json.kt:165)
	at io.ktor.serialization.kotlinx.KotlinxSerializationConverter.deserialize(KotlinxSerializationConverter.kt:69)
	... 50 more
Caused by: kotlinx.serialization.MissingFieldException: Fields [name, slug] are required for type with serial name 'com.bumble.sdlc.github.model.InstallationAccount', but they were missing
	at kotlinx.serialization.internal.PluginExceptionsKt.throwMissingFieldException(PluginExceptions.kt:20)
	at com.bumble.sdlc.github.model.InstallationAccount.<init>(InstallationAccount.kt:40)
	at com.bumble.sdlc.github.model.InstallationAccount$$serializer.deserialize(InstallationAccount.kt:40)
	at com.bumble.sdlc.github.model.InstallationAccount$$serializer.deserialize(InstallationAccount.kt:40)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:69)
	... 66 more