Simplify API Versioning Config in WebTestClient

[hantsy]

Java 21/Spring 7.0.0-M7/Spring Boot 4.0.0-M1, I attempted to write test code for the API with versioning. When building WebTestClient and setting up apiVersioning is not enough, an exception indicates that it requires ApiVersionInserter. I need to use both configurations together to get it to work.

this.webTestClient = WebTestClient
        .bindToController(new GreetingController())
        .apiVersioning(apiVersionConfigurer ->
                apiVersionConfigurer.useRequestHeader("X-API-Version").setDefaultVersion("1.0"))
        .configureClient()
        .apiVersionInserter(ApiVersionInserter.builder()
                .useHeader("X-API-Version")
                .build())
        .build();

[rstoyanchev]

I see your point but I don't see a good solution. The challenge is that WebTestClient involves a client and a server, both need to be configurable, and the strategies are different. So you might have a custom implementation that should be possible to plug in, or you might want to test sending a bad request.

Did you have a concrete proposal?

[hantsy]

In my opinion, focus on the API versioning at the configuring client stage.

Keep with:

.configureClient()
        .apiVersionInserter(ApiVersionInserter.builder()
                .useHeader("X-API-Version")
                .build())

And provides consistent config with the clients(RestClient/RestTemplate, WebClient,...)

[rstoyanchev]

That is what we have, but what about the server?

On the client side it's a simple version inserter and formatter, on the server side it's a version resolver, parser, validator (all that's on ApiVersionConfigurer). You can't take client config and fill in the server config.

Even if we did so for simple cases, you still need to be able to configure every setting on the server. What's being tested after all is the server, not the client.

[hantsy]

Of course, the client and server config should be separated.

On the server, I hope the config can be extracted from WebMvc/WebFluxConfigurer, use a bean ApiVersionStretagy some like etc. to organize them.

[rstoyanchev]

If the WebTestClient is created with bindToApplicationContext with a context that contains the WebMvc/WebFlux config, then yes, you can skip the apiVersioning step in the setup. However, with bindToControler there is no configuration, it all needs to be set up.