WebTestClient.ResponseSpec.expectBodyList not working with kotlinx-serialization module #36187

package com.example.kotlin_serialization_bug

import kotlinx.serialization.Serializable
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.RestController

@Serializable data class Response(val message: String)

@RestController
class ExampleController {
    @GetMapping("test")
    suspend fun test(): List<Response> =
        listOf(
            Response("Hello"),
            Response("World"),
        )
}

package com.example.kotlin_serialization_bug

import org.junit.jupiter.api.Test
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.boot.webflux.test.autoconfigure.WebFluxTest
import org.springframework.test.web.reactive.server.WebTestClient

@WebFluxTest(ExampleController::class)
class ExampleControllerTest(@param:Autowired private val webTestClient: WebTestClient) {
    @Test
    suspend fun testEndpoint() {
        webTestClient
            .get()
            .uri("/test")
            .exchangeSuccessfully()
            .expectBodyList(Response::class.java)
            .hasSize(2)
    }
}