Fix NullReferenceException when using a gateway before instance is cr…

…eated (#848)

src/Altinn.App.Core/Internal/Data/CachedInstanceDataAccessor.cs

@@ -18,8 +18,6 @@ namespace Altinn.App.Core.Internal.Data;
 internal sealed class CachedInstanceDataAccessor : IInstanceDataMutator
 {
     // DataClient needs a few arguments to fetch data
-    private readonly string _org;
-    private readonly string _app;
     private readonly Guid _instanceGuid;
     private readonly int _instanceOwnerPartyId;
 
@@ -60,12 +58,13 @@ public CachedInstanceDataAccessor(
         ModelSerializationService modelSerializationService
     )
     {
-        var splitApp = instance.AppId.Split("/");
-        _org = splitApp[0];
-        _app = splitApp[1];
-        var splitId = instance.Id.Split("/");
-        _instanceOwnerPartyId = int.Parse(splitId[0], CultureInfo.InvariantCulture);
-        _instanceGuid = Guid.Parse(splitId[1]);
+        if (instance.Id is not null)
+        {
+            var splitId = instance.Id.Split("/");
+            _instanceOwnerPartyId = int.Parse(splitId[0], CultureInfo.InvariantCulture);
+            _instanceGuid = Guid.Parse(splitId[1]);
+        }
+
         Instance = instance;
         _dataClient = dataClient;
         _appMetadata = appMetadata;
@@ -93,18 +92,27 @@ public async Task<object> GetFormData(DataElementIdentifier dataElementIdentifie
     }
 
     /// <inheritdoc />
-    public async Task<ReadOnlyMemory<byte>> GetBinaryData(DataElementIdentifier dataElementIdentifier) =>
-        await _binaryCache.GetOrCreate(
+    public async Task<ReadOnlyMemory<byte>> GetBinaryData(DataElementIdentifier dataElementIdentifier)
+    {
+        if (_instanceOwnerPartyId == 0 || _instanceGuid == Guid.Empty)
+        {
+            throw new InvalidOperationException("Cannot access instance data before it has been created");
+        }
+
+        var appMetadata = await _appMetadata.GetApplicationMetadata();
+
+        return await _binaryCache.GetOrCreate(
             dataElementIdentifier,
             async () =>
                 await _dataClient.GetDataBytes(
-                    _org,
-                    _app,
+                    appMetadata.AppIdentifier.Org,
+                    appMetadata.AppIdentifier.App,
                     _instanceOwnerPartyId,
                     _instanceGuid,
                     dataElementIdentifier.Guid
                 )
         );
+    }
 
     /// <inheritdoc />
     public DataElement GetDataElement(DataElementIdentifier dataElementIdentifier)
@@ -230,6 +238,11 @@ public List<DataElementChange> GetDataElementChanges(bool initializeAltinnRowId)
 
     internal async Task UpdateInstanceData(List<DataElementChange> changes)
     {
+        if (_instanceOwnerPartyId == 0 || _instanceGuid == Guid.Empty)
+        {
+            throw new InvalidOperationException("Cannot access instance data before it has been created");
+        }
+
         var tasks = new List<Task>();
         ConcurrentBag<DataElement> createdDataElements = new();
         // We need to create data elements here, so that we can set them correctly on the instance
@@ -258,14 +271,16 @@ async Task InsertBinaryData()
             tasks.Add(InsertBinaryData());
         }
 
+        var appMetadata = await _appMetadata.GetApplicationMetadata();
+
         // Delete data elements
         foreach (var dataElementId in _dataElementsToDelete)
         {
             async Task DeleteData()
             {
                 await _dataClient.DeleteData(
-                    _org,
-                    _app,
+                    appMetadata.AppIdentifier.Org,
+                    appMetadata.AppIdentifier.App,
                     _instanceOwnerPartyId,
                     _instanceGuid,
                     dataElementId.Guid,

test/Altinn.App.Core.Tests/Internal/Process/ProcessEngineTest.cs

@@ -13,6 +13,7 @@
 using Altinn.App.Core.Internal.Process.Elements;
 using Altinn.App.Core.Internal.Process.ProcessTasks;
 using Altinn.App.Core.Internal.Profile;
+using Altinn.App.Core.Models;
 using Altinn.App.Core.Models.Process;
 using Altinn.App.Core.Models.UserAction;
 using Altinn.Platform.Profile.Models;
@@ -457,6 +458,7 @@ public async Task Next_returns_unsuccessful_unauthorized_when_action_handler_ret
     [Fact]
     public async Task Next_moves_instance_to_next_task_and_produces_instanceevents()
     {
+        _appMetadataMock.Setup(x => x.GetApplicationMetadata()).ReturnsAsync(new ApplicationMetadata("org/app"));
         var expectedInstance = new Instance()
         {
             Id = _instanceId,
@@ -604,6 +606,7 @@ public async Task Next_moves_instance_to_next_task_and_produces_instanceevents()
     [Fact]
     public async Task Next_moves_instance_to_next_task_and_produces_abandon_instanceevent_when_action_reject()
     {
+        _appMetadataMock.Setup(x => x.GetApplicationMetadata()).ReturnsAsync(new ApplicationMetadata("org/app"));
         var expectedInstance = new Instance()
         {
             Id = _instanceId,
@@ -752,6 +755,7 @@ public async Task Next_moves_instance_to_next_task_and_produces_abandon_instance
     [Fact]
     public async Task Next_moves_instance_to_end_event_and_ends_proces()
     {
+        _appMetadataMock.Setup(x => x.GetApplicationMetadata()).ReturnsAsync(new ApplicationMetadata("org/app"));
         var expectedInstance = new Instance()
         {
             Id = _instanceId,

test/Altinn.App.Core.Tests/Internal/Process/ProcessTasks/Common/ProcessTaskFinalizerTests.cs

@@ -70,6 +70,7 @@ public async Task Finalize_WithValidInputs_ShouldCallCorrectMethods()
         await _processTaskFinalizer.Finalize(instance.Process.CurrentTask.ElementId, instance);
 
         // Assert
-        _appMetadataMock.Verify(x => x.GetApplicationMetadata(), Times.Once);
+        // Called once in Finalize and once in CachedInstanceDataAccessor.UpdateInstanceData
+        _appMetadataMock.Verify(x => x.GetApplicationMetadata(), Times.Exactly(2));
     }
 }