ClassCastException when using returning() with R2DBC

[lukaseder]

The following fails in jOOQ 3.15.2:

Flux.from(ctx.insertInto(TIdentityPK()).columns(TIdentityPK_VAL()).values(1).returning())
    .flatMap(i -> {
        assertTrue(i instanceof UpdatableRecord);
        ...

There is a ClassCastException. It seems we don't produce the correct record type with this particular API usage:

java.lang.ClassCastException: class org.jooq.impl.RecordImpl2 cannot be cast to class org.jooq.UpdatableRecord (org.jooq.impl.RecordImpl2 and org.jooq.UpdatableRecord are in unnamed module of loader 'app')
	at reactor.core.publisher.FluxFlatMap$FlatMapMain.onNext(FluxFlatMap.java:386)
	at org.jooq.impl.Internal$1.onNext(Internal.java:436)
	at org.jooq.impl.R2DBC$Forwarding.onNext(R2DBC.java:229)
	at reactor.core.publisher.StrictSubscriber.onNext(StrictSubscriber.java:89)
	at reactor.core.publisher.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:118)
	at reactor.core.publisher.MonoFlatMapMany$FlatMapManyInner.onNext(MonoFlatMapMany.java:250)
	at reactor.core.publisher.FluxHandleFuseable$HandleFuseableSubscriber.onNext(FluxHandleFuseable.java:184)
	at reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:337)
	at reactor.core.publisher.FluxContextWrite$ContextWriteSubscriber.onNext(FluxContextWrite.java:107)
	at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onNext(FluxPeekFuseable.java:854)
	at io.r2dbc.postgresql.util.FluxDiscardOnCancel$FluxDiscardOnCancelSubscriber.onNext(FluxDiscardOnCancel.java:86)
	at reactor.core.publisher.FluxCreate$BufferAsyncSink.drain(FluxCreate.java:793)
	at reactor.core.publisher.FluxCreate$BufferAsyncSink.next(FluxCreate.java:718)
	at reactor.core.publisher.FluxCreate$SerializedFluxSink.next(FluxCreate.java:154)
	at io.r2dbc.postgresql.client.ReactorNettyClient$Conversation.emit(ReactorNettyClient.java:717)
	at io.r2dbc.postgresql.client.ReactorNettyClient$BackendMessageSubscriber.emit(ReactorNettyClient.java:968)
	at io.r2dbc.postgresql.client.ReactorNettyClient$BackendMessageSubscriber.onNext(ReactorNettyClient.java:842)
	at io.r2dbc.postgresql.client.ReactorNettyClient$BackendMessageSubscriber.onNext(ReactorNettyClient.java:749)
	at reactor.core.publisher.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:118)
	at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onNext(FluxPeekFuseable.java:854)
	at reactor.core.publisher.FluxMap$MapConditionalSubscriber.onNext(FluxMap.java:220)
	at reactor.core.publisher.FluxMap$MapConditionalSubscriber.onNext(FluxMap.java:220)
	at reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:265)
	at reactor.netty.channel.FluxReceive.onInboundNext(FluxReceive.java:371)
	at reactor.netty.channel.ChannelOperations.onInboundNext(ChannelOperations.java:358)
	at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:96)
	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.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:324)
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:311)
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:432)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	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$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	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(Thread.java:833)
	Suppressed: java.lang.Exception: #block terminated with an error
		at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:99)
		at reactor.core.publisher.Mono.block(Mono.java:1703)
		at org.jooq.test.all.testcases.R2DBCTests.lambda$33(R2DBCTests.java:650)
		at org.jooq.test.jOOQAbstractTest.withDSLContext(jOOQAbstractTest.java:1608)
		at org.jooq.test.jOOQAbstractTest.bindAndInlineWithDSLContexts(jOOQAbstractTest.java:1601)
		at org.jooq.test.BaseTest.bindAndInlineWithDSLContexts(BaseTest.java:1645)
		at org.jooq.test.all.testcases.R2DBCTests.testR2DBCInsertReturningTableRecord(R2DBCTests.java:627)
		at org.jooq.test.jOOQAbstractTest.testR2DBCInsertReturningTableRecord(jOOQAbstractTest.java:2152)

[lukaseder]

The bug was not detected, because all of our integration tests are using returningResult() as of now

[lukaseder]

Fixed in jOOQ 3.16.0 and 3.15.3 (#12374). Thanks again, @azhurtbayev-klikatech, for your report here: #12370

[lucianogreiner]

There is a clear workaround for this using .returning().coerce

[lukaseder]

@lucianogreiner Or, you upgrade to 3.15.3?