Make HttpException implement CopyableThrowable + add test

retrofit/kotlin-test/src/test/java/retrofit2/KotlinSuspendTest.kt

@@ -18,6 +18,7 @@ package retrofit2
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.async
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
@@ -36,6 +37,9 @@ import retrofit2.http.GET
 import retrofit2.http.HEAD
 import retrofit2.http.Path
 import java.io.IOException
+import java.io.PrintWriter
+import java.io.StringWriter
+import java.lang.Runnable
 import java.lang.reflect.ParameterizedType
 import java.lang.reflect.Type
 import kotlin.coroutines.CoroutineContext
@@ -202,6 +206,58 @@ class KotlinSuspendTest {
     runBlocking { example.headUnit() }
   }
 
+  @Test fun await404() {
+    val retrofit = Retrofit.Builder()
+        .baseUrl(server.url("/"))
+        .addConverterFactory(ToStringConverterFactory())
+        .build()
+    val example = retrofit.create(Service::class.java)
+
+    server.enqueue(MockResponse().setResponseCode(404))
+
+    try {
+      runBlocking {
+        val deferred = async { example.body()  }
+
+        deferred.await()
+      }
+      fail()
+    } catch (e: HttpException) {
+      val writer = StringWriter()
+      e.printStackTrace(PrintWriter(writer))
+      val trace = writer.toString()
+
+      assertThat(trace).contains("KotlinSuspendTest")
+      assertThat(trace).contains("await404")
+    }
+  }
+
+  @Test fun launch404() {
+    val retrofit = Retrofit.Builder()
+        .baseUrl(server.url("/"))
+        .addConverterFactory(ToStringConverterFactory())
+        .build()
+    val example = retrofit.create(Service::class.java)
+
+    server.enqueue(MockResponse().setResponseCode(404))
+
+    try {
+      runBlocking {
+        val job = launch { example.body()  }
+
+        job.join()
+      }
+      fail()
+    } catch (e: HttpException) {
+      val writer = StringWriter()
+      e.printStackTrace(PrintWriter(writer))
+      val trace = writer.toString()
+
+      assertThat(trace).contains("KotlinSuspendTest")
+      assertThat(trace).contains("launch404")
+    }
+  }
+
   @Test fun params() {
     val retrofit = Retrofit.Builder()
         .baseUrl(server.url("/"))

retrofit/src/main/java/retrofit2/KotlinExtensions.kt

@@ -18,6 +18,7 @@
 
 package retrofit2
 
+import kotlinx.coroutines.CopyableThrowable
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.suspendCancellableCoroutine
 import java.lang.reflect.ParameterizedType
@@ -51,7 +52,7 @@ suspend fun <T : Any> Call<T>.await(): T {
             continuation.resume(body)
           }
         } else {
-          continuation.resumeWithException(HttpException(response))
+          continuation.resumeWithException(KotlinHttpException(response))
         }
       }
 
@@ -73,7 +74,7 @@ suspend fun <T : Any> Call<T?>.await(): T? {
         if (response.isSuccessful) {
           continuation.resume(response.body())
         } else {
-          continuation.resumeWithException(HttpException(response))
+          continuation.resumeWithException(KotlinHttpException(response))
         }
       }
 
@@ -124,3 +125,14 @@ internal suspend fun Exception.suspendAndThrow(): Nothing {
     COROUTINE_SUSPENDED
   }
 }
+
+private class KotlinHttpException(
+  private val response: Response<*>
+) : HttpException(response), CopyableThrowable<KotlinHttpException> {
+
+  override fun createCopy(): KotlinHttpException {
+    val result = KotlinHttpException(response)
+    result.initCause(this)
+    return result
+  }
+}