From d6ba02e29e56558c71d5fcbfd2104aeaa35f4792 Mon Sep 17 00:00:00 2001
From: Niclas Thobaben <niclas.thobaben@nclazz.de>
Date: Tue, 15 Feb 2022 13:01:31 +0100
Subject: [PATCH] Add QueryParams to error redirect from from #5

---
 .../mailrelay/ForwardMessageFormTest.java     |  5 ++---
 .../adapter/web/MessageFormController.java    | 19 ++++++++++++++++++-
 .../web/MessageFormControllerTest.java        |  1 -
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/integration/java/de/nclazz/service/mailrelay/ForwardMessageFormTest.java b/src/integration/java/de/nclazz/service/mailrelay/ForwardMessageFormTest.java
index f3d7447..fb4adad 100644
--- a/src/integration/java/de/nclazz/service/mailrelay/ForwardMessageFormTest.java
+++ b/src/integration/java/de/nclazz/service/mailrelay/ForwardMessageFormTest.java
@@ -19,8 +19,7 @@ import java.util.List;
 import java.util.UUID;
 
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.redirectedUrl;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;
 
 @SpringBootTest
 @ActiveProfiles("integration")
@@ -86,6 +85,6 @@ public class ForwardMessageFormTest {
                 .param("onError", "http://myerrorsite.com")
         )
                 .andExpect(status().is3xxRedirection())
-                .andExpect(redirectedUrl("http://myerrorsite.com"));
+                .andExpect(redirectedUrlPattern("http://myerrorsite.com?*"));
     }
 }
diff --git a/src/main/java/de/nclazz/service/mailrelay/adapter/web/MessageFormController.java b/src/main/java/de/nclazz/service/mailrelay/adapter/web/MessageFormController.java
index 0a04cdf..fdf2857 100644
--- a/src/main/java/de/nclazz/service/mailrelay/adapter/web/MessageFormController.java
+++ b/src/main/java/de/nclazz/service/mailrelay/adapter/web/MessageFormController.java
@@ -11,8 +11,11 @@ import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.annotation.RequestMapping;
 
 import javax.validation.Valid;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import java.time.Clock;
 import java.time.LocalDateTime;
+import java.util.stream.Collectors;
 
 @Controller
 @Slf4j
@@ -29,7 +32,7 @@ public class MessageFormController {
                                  BindingResult bindingResult) {
 
         if(bindingResult.hasErrors()) {
-            String onError = (form.getOnError() != null ? form.getOnError() : referer);
+            String onError = formatErrorRedirect(referer, form, bindingResult);
             return "redirect:" + onError;
         }
 
@@ -47,6 +50,20 @@ public class MessageFormController {
         return "redirect:" + redirect;
     }
 
+    private String formatErrorRedirect(String referer, MessageForm form, BindingResult bindingResult) {
+        String queryParams = bindingResult.getAllErrors().stream()
+                .map(ValidationError::fromObjectError)
+                .map(MessageFormController::mapValidationErrorToQueryParam)
+                .collect(Collectors.joining("&"));
+        String origin = form.getOnError() != null ? form.getOnError() : referer;
+
+        return origin + "?" + URLEncoder.encode(queryParams, StandardCharsets.UTF_8);
+    }
+
+    private static String mapValidationErrorToQueryParam(ValidationError error) {
+        return String.format("%s=%s", error.getTarget(), error.getMessage());
+    }
+
 
 
 }
diff --git a/src/test/java/de/nclazz/service/mailrelay/adapter/web/MessageFormControllerTest.java b/src/test/java/de/nclazz/service/mailrelay/adapter/web/MessageFormControllerTest.java
index e9862ac..69d2fc2 100644
--- a/src/test/java/de/nclazz/service/mailrelay/adapter/web/MessageFormControllerTest.java
+++ b/src/test/java/de/nclazz/service/mailrelay/adapter/web/MessageFormControllerTest.java
@@ -44,5 +44,4 @@ class MessageFormControllerTest {
                 .extracting("subject", "content", "from", "timestamp")
                 .containsExactly("Subject", "Message", "sender@company.com", now);
     }
-
 }
\ No newline at end of file