Merge pull request #5 from collectiveidea/add-service-exception-helper-for-not-modified

Add a helper to determine if an exception is from a `304 Not Modified` response.

Author: darronschall

runtime/src/commonMain/kotlin/com/collectiveidea/twirp/ServiceException.kt

@@ -1,6 +1,13 @@
 package com.collectiveidea.twirp
 
+import io.ktor.client.plugins.RedirectResponseException
 import io.ktor.client.plugins.ResponseException
+import io.ktor.http.HttpStatusCode
 
-class ServiceException(val error: ErrorResponse, responseException: ResponseException) :
-    RuntimeException(error.msg, responseException)
+class ServiceException(val error: ErrorResponse, val responseException: ResponseException) :
+    RuntimeException(error.msg, responseException) {
+
+    fun isNotModifiedException(): Boolean {
+        return responseException is RedirectResponseException && responseException.response.status == HttpStatusCode.NotModified
+    }
+}