RequestSpec.metadata(Consumer<RequestSpec>) not intuitive name

[rwinch]

The name for RSocketRequester RequestSpec.metadata(Consumer) is not very intuitive since it can modify the entire RequestSpec. I wonder if we should modify the name or change the argument?

[rstoyanchev]

The method returns RequestSpec so then you need to call data(...) to get to ResponseSpec. So in practice you can only use this to add metadata.

Data is not additive, unlike (composite) metadata, and that means it can only be set by one party. To allow setting both it would have to be something that takes over the request definition:

ResponseSpec apply(Function<ResponseSpec, RequestSpec) configurer);

[rwinch]

I see that invoking data won't work, but the API is still a bit confusing because I am providing a Consumer<RequestSpec> which allows me to invoke metadata just as easily as I am data.

[rstoyanchev]

This has been addressed as part of #23649 and is now:

RequestSpec metadata(Consumer<MetadataSpec<?>> configurer);