add response advice for annotated response wrapping

Author: MarvinSchramm

README.md

@@ -1,6 +1,9 @@
 package io.hndrs.api.sample
 
+import io.hndrs.api.response.JsonApiResponse
+import io.hndrs.api.response.Response
 import org.springframework.http.HttpStatus
+import org.springframework.http.ResponseEntity
 import org.springframework.web.bind.annotation.GetMapping
 import org.springframework.web.bind.annotation.RestController
 import org.springframework.web.server.ResponseStatusException
@@ -13,4 +16,27 @@ class SampleController {
     fun errors() {
         throw ResponseStatusException(HttpStatus.CONFLICT)
     }
+
+    @GetMapping("/address1")
+    @JsonApiResponse
+    fun annotated(): Address {
+        return Address()
+    }
+
+    @GetMapping("/address2")
+    fun wrapped(): Response<Address> {
+        return Response(Address())
+    }
+
+    @GetMapping("/address3")
+    @JsonApiResponse
+    fun annotatedResponseEntity(): ResponseEntity<Address> {
+        return ResponseEntity.ok(Address())
+    }
+
+    data class Address(
+        val street: String = "147 Bleecker St",
+        val locality: String = "New York",
+        val zip: String = "10012"
+    )
 }

sample/src/main/kotlin/io/hndrs/api/sample/SampleController.kt

@@ -1,4 +1,4 @@
 dependencies {
-    implementation(project(":spring-json-api"))
+    api(project(":spring-json-api"))
     testImplementation(group = "org.springframework.boot", name = "spring-boot-starter-test")
 }

spring-json-api-starter/build.gradle.kts

@@ -1,6 +1,7 @@
 package io.hndrs.api.autoconfigure
 
 import io.hndrs.api.exception.ExceptionHandler
+import io.hndrs.api.response.ResponseAdvise
 import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.Configuration
 
@@ -11,4 +12,9 @@ open class JsonApiAutoConfiguration {
     open fun exceptionAdvice(): ExceptionHandler {
         return ExceptionHandler()
     }
+
+    @Bean
+    open fun responseAdvice(): ResponseAdvise {
+        return ResponseAdvise()
+    }
 }

spring-json-api-starter/src/main/kotlin/io/hndrs/api/autoconfigure/JsonApiAutoConfiguration.kt

@@ -1,6 +1,7 @@
 package io.hndrs.api.autoconfigure
 
 import io.hndrs.api.exception.ExceptionHandler
+import io.hndrs.api.response.ResponseAdvise
 import org.junit.jupiter.api.Assertions
 import org.junit.jupiter.api.DisplayName
 import org.junit.jupiter.api.Test
@@ -17,6 +18,7 @@ internal class JsonApiAutoConfigurationTest {
                 AutoConfigurations.of(JsonApiAutoConfiguration::class.java)
             ).run {
                 Assertions.assertNotNull(it.getBean(ExceptionHandler::class.java))
+                Assertions.assertNotNull(it.getBean(ResponseAdvise::class.java))
             }
     }
 }

spring-json-api-starter/src/test/kotlin/io/hndrs/api/autoconfigure/JsonApiAutoConfigurationTest.kt

@@ -0,0 +1,38 @@
+package io.hndrs.api.response
+
+import org.springframework.core.MethodParameter
+import org.springframework.http.MediaType
+import org.springframework.http.ResponseEntity
+import org.springframework.http.converter.HttpMessageConverter
+import org.springframework.http.server.ServerHttpRequest
+import org.springframework.http.server.ServerHttpResponse
+import org.springframework.web.bind.annotation.ControllerAdvice
+import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice
+
+@ControllerAdvice
+class ResponseAdvise : ResponseBodyAdvice<Any> {
+
+    override fun beforeBodyWrite(
+        value: Any?,
+        returnType: MethodParameter,
+        selectedContentType: MediaType,
+        selectedConverterType: Class<out HttpMessageConverter<*>>,
+        request: ServerHttpRequest,
+        response: ServerHttpResponse
+    ): Any? {
+        return when (value) {
+            is ResponseEntity<*> -> ResponseEntity.status(value.statusCode).headers(value.headers).body(value.body)
+            null -> null
+            else -> Response(value)
+        }
+    }
+
+    override fun supports(returnType: MethodParameter, converterType: Class<out HttpMessageConverter<*>>): Boolean {
+        return returnType.method?.isAnnotationPresent(JsonApiResponse::class.java) ?: false
+    }
+}
+
+@Retention(AnnotationRetention.RUNTIME)
+@Target(AnnotationTarget.FUNCTION)
+annotation class JsonApiResponse
+

spring-json-api/src/main/kotlin/io/hndrs/api/response/ResponseAdvise.kt

@@ -1 +1 @@
-0.0.1
+1.0.0