binary alias return type appears to have the wrong content-type header

[robqliu]

What happened?

I'm using the dialogue client and it threw this exception when attempting to hit a conjure endpoint of an undertow server whose return type was an alias for 'binary':

ERROR [2020-09-29T06:35:04.005393Z] <redacted> {}. (<redacted>, throwable0_received: application/json, throwable0_supportedEncodings: [EncodingDeserializerContainer{encoding=BinaryEncoding{application/octet-stream}, deserializer=InputStreamDeserializer{}}])
com.palantir.logsafe.exceptions.SafeRuntimeException: Unsupported Content-Type
        at com.palantir.conjure.java.dialogue.serde.ConjureBodySerDe$EncodingDeserializerRegistry$1.deserialize(ConjureBodySerDe.java:298)
        at com.palantir.conjure.java.dialogue.serde.ConjureBodySerDe$EncodingDeserializerRegistry.deserialize(ConjureBodySerDe.java:257)
        at com.palantir.dialogue.futures.DialogueDirectTransformationFuture.onSuccess(DialogueDirectTransformationFuture.java:103)
        at com.google.common.util.concurrent.Futures$CallbackListener.run(Futures.java:1021)
        at com.palantir.dialogue.futures.SafeDirectExecutor.execute(SafeDirectExecutor.java:32)
        at com.google.common.util.concurrent.AbstractFuture.executeListener(AbstractFuture.java:1137)
        at com.google.common.util.concurrent.AbstractFuture.complete(AbstractFuture.java:957)
        at com.google.common.util.concurrent.AbstractFuture.set(AbstractFuture.java:726)
        at com.google.common.util.concurrent.AbstractFuture.complete(AbstractFuture.java:957)
        at com.google.common.util.concurrent.AbstractFuture.set(AbstractFuture.java:726)
        at com.google.common.util.concurrent.SettableFuture.set(SettableFuture.java:47)
...
        Suppressed: com.palantir.logsafe.exceptions.SafeRuntimeException: Rethrown by dialogue
                at com.palantir.conjure.java.dialogue.serde.DefaultClients.block(DefaultClients.java:124)
...

I was able to fix this by directly returning the binary type in my endpoint:

      <redacted>:
        http: PUT /<redacted>
        args:
          request:
            param-type: body
            type: <redacted>
        returns: binary

to be clear, it looked like this before

      <redacted>:
        http: PUT /<redacted>
        args:
          request:
            param-type: body
            type: <redacted>
        returns: Foo

      Foo:
        alias: binary

What did you want to happen?

Seems like binary aliases should work as return types. Not sure if this is a bug in the dialogue client or in the undertow endpoint generated.

[bmoylan]

+1 I noticed this recently when trying to update conjure-go to correctly reflect the conjure-verification BinaryAliasExample test cases. The verifier is expecting these to be JSON serialized (quoted, base64, json content-type) where I expected to match the behavior for plain binary types.

[carterkozak]

@bubchi89 Yep, this is a bug where we fail to dealias the top-level type, and incorrectly expect json instead of application/octet stream. Let's move this ticket to the correct project please https://github.com/palantir/conjure-java

@bmoylan I think the verifier is broken in a similar way. Would you mind filing an issue on the https://github.com/palantir/conjure-verification project?

[bmoylan]

Actually it looks like the verifier issue was already filed here: palantir/conjure-verification#296

[carterkozak]

Closing this in favor of palantir/conjure-java#1099
fix is up: palantir/conjure-java#1102