Heya, have you run into other Kotlin/Java code generators from OpenAPI than https://github.com/OpenAPITools/openapi-generator/ and https://github.com/swagger-api/swagger-codegen ? They both leave a lot to be desired on the generating model classes side (not to mention, say, clients) with quite buggy implementations compared to, say, OpenAPI Typescript generator.

Yes, I’ve used them but the generations is indeed quite bad. It’s practically unuseable from my experience 😞 I’ve only looked at KotlinX Serialization/Ktor though, and I’ve had to resort to writing custom templates in some cases. To for example generate only models, and write client by hand. I’ve considered writing a custom generator, but lack the time atm for it unless I can do it as part of my actual work.

I mean, I've tried all Java/Kotlin generators and for some basic cases they work. But in general the create uncompilable stuff or just drop some things. Even for models. I was wondering if there are some tools I've missed as I've also thought about creating my own tooling (which is quite a big ask for general case).

Http4k wrote our own generator (see Https://toolbox.http4k.org) for precisely that reason -the official template-based implementations leave a lot to be desired. It is quite tricky though TBF - the malleability of the spec (and the number of people who are using hand rolled illegal specs makes it even harder). 🙃

and the number of people who are using hand rolled illegal specs makes it even harder

💯

We decided on Kotlin poet for the generation - at least then you are quite assured that it compiles. Plus we test it.. 😉

Thanks, I'll check if your generator generates better (or, well, just working) code in our cases for models.

@Jarkko Miettinen yes - the source code of the generator isn't open source unfortunately. In terms of the test case - can you share the URL you were using and we can try to look at why it failed. If you get a 400, then what would be handy is to paste the content of the response (it should contain trace information which we use to determine why the generator didn't like the spec).

Oki, that's fine and also a point towards writing our own solution or changing the approach to API -> spec. Trace id is 9bef7a1fa03f58a8

not the trace id - the content of the message 🙂

You mean my request? As that's all the http4k-cli gives out as a response message.

ah ok. That indicates that it couldn't even parse the input file. Did you upload a file or a URL?

I uploaded this file. Which gives me constant 400. I'd wager it's this oneOf many enums thing that I tried to be able to write descriptions for permission inline instead of having them in a separate description in the container object.

The response does contain the log BTW. I'll take a look when I get a chance 🙂

Yeah, allOf maps nicely but for oneOf you’ll need a sealed type hierarchy. OpenAPITools don’t fail to generate, they just create non-sense 😀 . I was thinking that for a hand-rolled generator these could be supported but problem would be that if you A|B|C in one place and B|C p, B in the two places would be a different type. Which could still be okay for limited use as long as you’d generate some helpers. I didn’t notice the response, should’ve used directly the web tool with inspector