FieldAccessException should include field as well as global errors in its message

[busches]

When making a GraphQl Client call to a field that returns a list of an entity, when then list is empty, we're getting the following error:

 org.springframework.graphql.client.FieldAccessException: Invalid field 'getRefillNumbers', errors: []
	at org.springframework.graphql.client.DefaultGraphQlClient$RetrieveSpecSupport.getValidField(DefaultGraphQlClient.java:183)
	at org.springframework.graphql.client.DefaultGraphQlClient$DefaultRetrieveSpec.lambda$toEntityList$2(DefaultGraphQlClient.java:213)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:113)
	at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1816)
	at reactor.core.publisher.MonoFlatMap$FlatMapInner.onNext(MonoFlatMap.java:249)
	at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:79)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:127)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:127)
	at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1816)
	at reactor.core.publisher.MonoFlatMap$FlatMapInner.onNext(MonoFlatMap.java:249)
	at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:79)
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:539)
	at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1816)
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:151)
	at reactor.core.publisher.FluxContextWrite$ContextWriteSubscriber.onNext(FluxContextWrite.java:107)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:295)
	at reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:337)
	at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1816)
	at reactor.core.publisher.MonoCollect$CollectSubscriber.onComplete(MonoCollect.java:159)
	at reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:142)
	at reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:260)
	at reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:142)
	at reactor.netty.channel.FluxReceive.onInboundComplete(FluxReceive.java:400)
	at reactor.netty.channel.ChannelOperations.onInboundComplete(ChannelOperations.java:419)
	at reactor.netty.channel.ChannelOperations.terminate(ChannelOperations.java:473)
	at reactor.netty.http.client.HttpClientOperations.onInboundNext(HttpClientOperations.java:703)
	at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:93)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:436)
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:327)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:299)
	at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1372)
	at io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1235)
	at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1284)
	at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:510)
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:449)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:279)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:800)
	at io.netty.channel.epoll.AbstractEpollChannel$AbstractEpollUnsafe$1.run(AbstractEpollChannel.java:425)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:469)
	at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:384)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Unknown Source)

Version: implementation("org.springframework.graphql:spring-graphql:1.0.0-M6")

Calling Code:

 val response = graphQlClient.documentName(documentName)
            .variables(variables)
            .retrieve("getRefillNumbers")
            .toEntityList(GetRefillNumbers::class.java)

Failing response:

{
	"data": {
		"getRefillNumbers": []
	}
}

Successful response:

{
	"data": {
		"getRefillNumbers": [
			{
				"somedata": "1860"
			}
       ]
}

I would not expect an empty array to result in an error, when it still technically follows the schema, additionally, the error thrown is very misleading, since the field getRefillNumbers is still there.

[rstoyanchev]

On closer look, I am unable to reproduce and I can't see why it's happening.

If you look at the line where the exception is raised, the response must be invalid of there is a field error. The former is defined as "data" is not present or null, which is not the case. For the latter, your snippet shows no "errors" at all, and the exception message confirms no field errors with errors [].

Could you please, either debug further based on this information to understand why it's raising the error, or provide a sample? Also, try using the latest snapshot, just in case.

[busches]

@rstoyanchev thanks, I'll double check if errors is populated or not, I'd find it pretty odd if it's there when there's values in the array and not when the array is empty. I likely just left it out of the response, since it also had all the federation stuff with it, but that's an easy thing to test.

Also in your tests, were you using M6 or what version to recreate?

[busches]

Confirmed that it's only data, no errors block, but I was not able to recreate it in a reproduction project. The production code is still having this issue, so I'll see if using that project I can recreate it.

[busches]

Ok, and I was finally able to recreate it, but the response was only errors with a null data. The error makes sense now, but I had to add more code to trap it to see the actual response bubbled up.

{
	"errors": [
		{
			"message": "401: Unauthorized",
			"extensions": {
				"code": "UNAUTHENTICATED"
			},
			"code": "UNAUTHENTICATED"
		}
	],
	"data": null,
	"extensions": {
		"tracing": {
			"version": 1,
			"startTime": "2022-04-21T14:46:53.732Z",
			"endTime": "2022-04-21T14:46:53.752Z",
			"duration": 20235956,
			"execution": {
				"resolvers": []
			}
		}
	}
}

Confirmed we get the same error in RC1, so the error message looks correct for what I'm seeing, I just wish it'd bubble up the response by default. :)

We're trapping and rethrowing like so:

            .onErrorMap { error ->
                if (error is GraphQlTransportException && error.cause is WebClientResponseException) {
                    val responseBody = (error.cause as WebClientResponseException).responseBodyAsString
                    GraphQLException("GraphQL call failed, ${error.message}, responseBody: $responseBody")
                } else if (error is FieldAccessException) { // This is the new case for the above response
                    GraphQLException("GraphQL call failed, ${error.message}, responseBody: ${error.response}")
                } else {
                    logger.error("Unhandled GraphQl Error, type was ${error.javaClass}")
                    error
                }
            }

Given this, I think we can close this, thanks!

[rstoyanchev]

On closer look, it's true that FieldAccessException can be raised because of a global, request-level error but its message does not take that into account and prints only field errors. I'm re-opening to improve the error message.