Is there a way to look deeper into `KoTypeDeclarat...

# konsist

[ceedee]

Is there a way to look deeper into KoTypeDeclarations? I want to find issues in Android Retrofit service implementations, where a non-basic Kotlin type is used that does not end on the suffix “Dto”, like this:

interface UrlShortenerService {

    @POST("short")
    @FormUrlEncoded
    fun getShortUrls(
        @Field("url") urls: List<Url>,
        @Field("expire") expireDate: String
    ): Single<List<UrlShortenerResponseDto>>
}

In the above example, Url is not ending on Dto - but I want to enforce that.

I have created this test:

@Test
    fun `all interface methods annotated with HTTP verbs only use DTO classes`() {
        Konsist
            .scopeFromProject()
            .interfaces()
            .assertTrue { classDeclaration ->
                classDeclaration
                    .functions(includeNested = false, includeLocal = false)
                    .all { method ->
                        !hasHttpVerbAnnotation(method) ||
                            method.parameters.all { parameter ->
                                isKotlinTypeOrDtoClass(parameter.type)
                            } && isKotlinTypeOrDtoClassOrUnit(method.returnType)
                    }
            }
    }

    private fun isKotlinTypeOrDtoClass(type: KoTypeDeclaration) = type.isKotlinType || type.name.endsWith("Dto")

    private fun isKotlinTypeOrDtoClassOrUnit(type: KoTypeDeclaration?) = type?.let { isKotlinTypeOrDtoClass(it) } ?: true

    private fun hasHttpVerbAnnotation(method: KoFunctionDeclaration) = method.hasAnnotation { annotation ->
        annotation.name == "POST" ||
            annotation.name == "GET" ||
            annotation.name == "PUT" ||
            annotation.name == "PATCH" ||
            annotation.name == "DELETE" ||
            annotation.name == "HEAD"
    }

But as isKotlinType returns true for Collections like List, this is not sufficient to detect the case I mentioned above. I could check for isGenericType but that does not tell me WHICH type is used there. Is there a way to achieve this?