PLAT-11641 handle json serialisation errors and remove payloads

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## TBD ()
+
+### Enhancements
+
+- Improved handling of serialisation errors when flushing the event cache [#773](https://github.com/bugsnag/bugsnag-unity/pull/773)
+
 ## 7.7.1 (2024-01-25)
 
 ### Bug Fixes

features/csharp/csharp_persistence.feature

@@ -103,3 +103,15 @@ Feature: Unity Persistence
     And the exception "message" equals "PersistDeviceId"
     And the error payload field "events.0.device.id" equals the stored value "device_id"
 
+  Scenario: Handle Corrupt Json
+    And I run the game in the "CorruptedCacheFile" state
+    And I wait for requests to persist
+    And I close the Unity app
+    And On Mobile I relaunch the app
+    And I run the game in the "PersistEventReport" state
+    And I wait for requests to persist
+    And I wait to receive 1 errors
+    And the error is valid for the error reporting API sent by the Unity notifier
+    And the exception "message" equals "Error 2"
+
+

features/fixtures/maze_runner/Assets/Scenes/MainScene.unity

@@ -38,7 +38,7 @@ RenderSettings:
   m_ReflectionIntensity: 1
   m_CustomReflection: {fileID: 0}
   m_Sun: {fileID: 0}
-  m_IndirectSpecularColor: {r: 0.3731192, g: 0.38073966, b: 0.35872677, a: 1}
+  m_IndirectSpecularColor: {r: 0.3731316, g: 0.38074902, b: 0.3587254, a: 1}
   m_UseRadianceAmbientProbe: 0
 --- !u!157 &3
 LightmapSettings:
@@ -1537,6 +1537,7 @@ GameObject:
   - component: {fileID: 1523264808}
   - component: {fileID: 1523264809}
   - component: {fileID: 1523264810}
+  - component: {fileID: 1523264811}
   m_Layer: 0
   m_Name: Persistence
   m_TagString: Untagged
@@ -1678,6 +1679,21 @@ MonoBehaviour:
   CustomStacktrace: 'Main.CUSTOM1 () (at Assets/Scripts/Main.cs:123)
 
     Main.CUSTOM2 () (at Assets/Scripts/Main.cs:123)'
+--- !u!114 &1523264811
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 1523264801}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 395039af028ee4010baf61afa7f7e066, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  CustomStacktrace: 'Main.CUSTOM1 () (at Assets/Scripts/Main.cs:123)
+
+    Main.CUSTOM2 () (at Assets/Scripts/Main.cs:123)'
 --- !u!1 &1746155638
 GameObject:
   m_ObjectHideFlags: 0

features/fixtures/maze_runner/Assets/Scripts/Scenarios/Csharp/Persistence/CorruptedCacheFile.cs

@@ -0,0 +1,27 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+using UnityEngine;
+
+public class CorruptedCacheFile : Scenario
+{
+
+    public override void PrepareConfig(string apiKey, string host)
+    {
+        base.PrepareConfig(apiKey, host);
+        if (Application.platform == RuntimePlatform.IPhonePlayer)
+        {
+            Configuration.EnabledErrorTypes.OOMs = false;
+        }
+    }
+
+    public override void Run()
+    {
+        var dirPath = Application.persistentDataPath + "/Bugsnag/Events";
+        if (!Directory.Exists(dirPath))
+        {
+            Directory.CreateDirectory(dirPath);
+        }
+        File.WriteAllText(dirPath + "/f04274f7-6f7d-448e-b62e-486cc019a708.event", "NOT JSON");
+    }
+}

src/BugsnagUnity/Delivery.cs

@@ -524,21 +524,51 @@ private IEnumerator ProcessCachedItems(Type t)
 
                     try
                     {
+                        // if something goes wrong at this stage then we silently discard the file as it's most likely that the file wasn't fully serialised to disk
                         payloadDictionary = ((JsonObject)SimpleJson.DeserializeObject(payloadJson)).GetDictionary();
                     }
-                    catch (Exception e)
+                    catch
                     {
-                        Debug.LogException(new Exception("Bugsnag Error. Deserialising a cached payload for delivery failed: " + e.Message + " Cached json: " + payloadJson));
+                        if (isSession)
+                        {
+                            _cacheManager.RemoveCachedSession(id);
+                        }
+                        else
+                        {
+                            _cacheManager.RemoveCachedEvent(id);
+                        }
                         continue;
                     }
 
                     if (isSession)
                     {
-                        Deliver(new SessionReport(_configuration, payloadDictionary));
+                        SessionReport sessionReport = null;
+                        try
+                        {
+                            sessionReport = new SessionReport(_configuration, payloadDictionary);
+                        }
+                        catch
+                        {
+                            // this will be internally reported in a future update
+                            _cacheManager.RemoveCachedSession(id);
+                            continue;
+                        }
+                        Deliver(sessionReport);
                     }
                     else
                     {
-                        Deliver(new Report(_configuration, payloadDictionary));
+                        Report report = null;
+                        try
+                        {
+                            report = new Report(_configuration, payloadDictionary);
+                        }
+                        catch
+                        {
+                            // this will be internally reported in a future update
+                            _cacheManager.RemoveCachedEvent(id);
+                            continue;
+                        }
+                        Deliver(report);
                     }
 
                     yield return new WaitUntil(() => CachedPayloadProcessed(id));

src/BugsnagUnity/Native/Fallback/CacheManager.cs

@@ -188,9 +188,13 @@ private void DeleteFile(string path)
 
         private void WriteFile(string path, string data)
         {
+            // not using File.WriteAllText to avoid under the hood buffering. We want the file to be written immediately to avoid truncation in case of a crash
             try
             {
-                File.WriteAllText(path, data);
+                var file = File.Create(path);
+                file.Write(System.Text.Encoding.UTF8.GetBytes(data), 0, data.Length);
+                file.Flush();
+                file.Close();
             }catch { }
         }