Integration with mock-server

[vitaliihonta]

Hi there! Do you plan to have any integration with mock-server https://www.mock-server.com/ ?
It seems to be useful for integration testing.

I tried to implement it myself but the implementation seems to rely on tapir internals.
Are you open to support such functionality?
I would like to contribute if possible 😄

[adamw]

We didn't have any plans, how could such an integration look like - that is, what would be its functionalities?

[ghostbuster91]

For now there is live-stub which is a very minimalistic version of such mock.
If you really need mock-server maybe you can use its implementation as a guidance? Is this something what you had in mind?

[vitaliihonta]

@adamw @ghostbuster91 my idea is to implement a converter between tapir's Endpoint and mock-server expectation. You already have a stub server that does something similar.
For example, having such endpoint:

case class Foo(x: Int)
case class Bar(y: String)

val helloEndpoint = endpoint.get.in("api" / "v1" / "hello").in(anyJsonBody[Foo]).out(anyJsonBody[Bar])

the module will translate it into mock-server interaction using the following "DSL" :

import sttp.tapir.mockserver._

val mockServerClient: MockServerClient = ???

val input = Foo(1)
val stubbedOutput = Bar("result")

val expectation: F[...] = helloEndpoint.toMockServerExpectation(mockServerClient)(input)(stubbedOutput)

This should be equivalent to direct mock-server-client usage:

mockServerClient
    .when(
        request()
            .withMethod("GET")
            .withPath("/api/v1/hello")
            .withBody("""{ "x": 1 }""")
    )
    .respond(
        response()
            .withBody("""{ "y" : "result" }""")
    )

It may be useful for integration testing or e2e tests with external services mocked.

I also believe such "translation" logic may be reused to implement the same functionality for your live-stub 😉

[adamw]

@vitaliihonta thanks for the explanation, makes sense! Of course contributions are possible and welcome :)

[ghostbuster91]

For live-stub there is already such dsl, see the sdk section. Still, it would be great to have something like that for mock-server.