[kotlin] Add integration test for query params

This is a test for a regression from OpenAPITools#22512 where param values
were written as a list.

Author: pkubowicz

samples/client/petstore/kotlin-jvm-spring-3-restclient/build.gradle

@@ -66,6 +66,7 @@ dependencies {
     implementation "com.fasterxml.jackson.module:jackson-module-kotlin:2.20.0"
     implementation "com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.20.0"
     implementation "org.springframework.boot:spring-boot-starter-web:$spring_boot_version"
+    testImplementation "org.springframework.boot:spring-boot-test:$spring_boot_version"
     testImplementation "io.kotlintest:kotlintest-runner-junit5:3.4.2"
 }
 

samples/client/petstore/kotlin-jvm-spring-3-restclient/src/test/kotlin/org/openapitools/integration/PetApiTest.kt

@@ -0,0 +1,35 @@
+package org.openapitools.integration
+
+import io.kotlintest.matchers.collections.shouldHaveSize
+import io.kotlintest.specs.ShouldSpec
+import org.openapitools.client.apis.PetApi
+import org.springframework.boot.test.web.client.MockServerRestClientCustomizer
+import org.springframework.http.HttpMethod
+import org.springframework.http.MediaType.APPLICATION_JSON
+import org.springframework.test.web.client.match.MockRestRequestMatchers.method
+import org.springframework.test.web.client.match.MockRestRequestMatchers.requestTo
+import org.springframework.test.web.client.response.MockRestResponseCreators.withSuccess
+import org.springframework.web.client.RestClient
+
+class PetApiTest : ShouldSpec() {
+    init {
+        should("find by status passing a query parameter with a list of values") {
+            val restClientBuilder: RestClient.Builder = RestClient.builder()
+            val mockServer = MockServerRestClientCustomizer().let {
+                it.customize(restClientBuilder)
+                it.getServer(restClientBuilder)
+            }
+            val petApi = PetApi(restClientBuilder.build())
+
+            mockServer.expect(requestTo("/pet/findByStatus?status=pending,available"))
+                .andExpect(method(HttpMethod.GET))
+                .andRespond(withSuccess("[]", APPLICATION_JSON))
+
+            val response = petApi.findPetsByStatus(listOf(PetApi.StatusFindPetsByStatus.pending, PetApi.StatusFindPetsByStatus.available))
+
+            mockServer.verify()
+
+            response shouldHaveSize 0
+        }
+    }
+}

samples/client/petstore/kotlin-jvm-spring-3-restclient/src/test/kotlin/org/openapitools/integration/UserApiTest.kt

@@ -0,0 +1,35 @@
+package org.openapitools.integration
+
+import io.kotlintest.shouldBe
+import io.kotlintest.specs.ShouldSpec
+import org.openapitools.client.apis.UserApi
+import org.springframework.boot.test.web.client.MockServerRestClientCustomizer
+import org.springframework.http.HttpMethod
+import org.springframework.http.MediaType.TEXT_PLAIN
+import org.springframework.test.web.client.match.MockRestRequestMatchers.method
+import org.springframework.test.web.client.match.MockRestRequestMatchers.requestTo
+import org.springframework.test.web.client.response.MockRestResponseCreators.withSuccess
+import org.springframework.web.client.RestClient
+
+class UserApiTest : ShouldSpec() {
+    init {
+        should("call login user passing a query parameter with a single value") {
+            val restClientBuilder: RestClient.Builder = RestClient.builder()
+            val mockServer = MockServerRestClientCustomizer().let {
+                it.customize(restClientBuilder)
+                it.getServer(restClientBuilder)
+            }
+            val userApi = UserApi(restClientBuilder.build())
+
+            mockServer.expect(requestTo("/user/login?username=myUsername&password=myPassword"))
+                .andExpect(method(HttpMethod.GET))
+                .andRespond(withSuccess("login response", TEXT_PLAIN))
+
+            val response = userApi.loginUser("myUsername", "myPassword")
+
+            mockServer.verify()
+
+            response shouldBe "login response"
+        }
+    }
+}