Temporary workaround for handling Http NotFound exception in MemoryStoreExtender

CHANGELOG.md

@@ -24,6 +24,7 @@ Previous classification is not required if changes are simple or all belong to t
 - Added an example of using `KeyPhrasesLocaled` in `Encamina.Enmarcha.Samples.SemanticKernel.Text`.
 - New text prompt function for translate texts, `Translate`.
 - Added an example of using `Translate` in `Encamina.Enmarcha.Samples.SemanticKernel.Text`.
+- Bug fix: Temporary workaround for handling Http NotFound exception in `MemoryStoreExtender`. [(#72)](https://github.com/Encamina/enmarcha/issues/72)
 
 ## [8.1.2]
 

Directory.Build.props

@@ -17,7 +17,7 @@
 
   <PropertyGroup>
     <VersionPrefix>8.1.3</VersionPrefix>
-    <VersionSuffix>preview-03</VersionSuffix>
+    <VersionSuffix>preview-04</VersionSuffix>
   </PropertyGroup>
 
   <!--

src/Encamina.Enmarcha.SemanticKernel/MemoryStoreExtender.cs

@@ -1,10 +1,12 @@
 // Ignore Spelling: Upsert
 
-using System;
 using System.Collections.ObjectModel;
+using System.Net;
 using System.Runtime.CompilerServices;
 using System.Text.Json;
 
+using Azure;
+
 using Encamina.Enmarcha.SemanticKernel.Abstractions;
 using Encamina.Enmarcha.SemanticKernel.Abstractions.Events;
 
@@ -45,7 +47,7 @@
     public void RaiseMemoryStoreEvent(MemoryStoreEventArgs e) => MemoryStoreEvent?.Invoke(this, e);
 
     /// <inheritdoc/>
     public virtual async Task UpsertMemoryAsync(string memoryId, string collectionName, IEnumerable<string> chunks, Kernel kernel, IDictionary<string, string> metadata = null, CancellationToken cancellationToken = default)
     {
         await DeleteMemoryAsync(memoryId, collectionName, cancellationToken);
         await SaveChunks(memoryId, collectionName, chunks, metadata, kernel, cancellationToken);
@@ -85,7 +87,7 @@
     }
 
     /// <inheritdoc/>
     public virtual async IAsyncEnumerable<string> BatchUpsertMemoriesAsync(string collectionName, IDictionary<string, MemoryContent> memoryContents, Kernel kernel, [EnumeratorCancellation] CancellationToken cancellationToken)
     {
         var memoryRecords = new List<MemoryRecord>();
         var textEmbeddingGenerationService = kernel.GetRequiredService<ITextEmbeddingGenerationService>();
@@ -132,15 +134,30 @@
     private async Task<int> GetChunkSize(string memoryId, string collectionName, CancellationToken cancellationToken)
     {
         var key = BuildMemoryIdentifier(memoryId, 0);
-        var fistMemoryChunk = await MemoryStore.GetAsync(collectionName, key, cancellationToken: cancellationToken);
+        MemoryRecord firstMemoryChunk = null;
+
+        try
+        {
+            firstMemoryChunk = await MemoryStore.GetAsync(collectionName, key, cancellationToken: cancellationToken);
+        }
+        catch (RequestFailedException e) when (e.Status == (int)HttpStatusCode.NotFound)
+        {
+            // At this point, we need to catch the NotFound exception. This is necessary because, in the case of Azure AI Search Memory Store,
+            // if the element does not exist, it throws an exception instead of returning a null value, which would be the expected behavior.
+            // We have opened an issue in Semantic Kernel and also an issue in ENMARCHA to track the progress of this issue and remove this try/catch block once it is resolved.
+            // Issue ENMARCHA: https://github.com/Encamina/enmarcha/issues/72
+
+            /* Do nothing */
+        }
+
         RaiseMemoryStoreEvent(new() { EventType = MemoryStoreEventTypes.Get, Keys = [key], CollectionName = collectionName });
 
-        if (fistMemoryChunk == null)
+        if (firstMemoryChunk == null)
         {
             return 0;
         }
 
-        var metadata = JsonSerializer.Deserialize<Dictionary<string, string>>(fistMemoryChunk.Metadata.AdditionalMetadata);
+        var metadata = JsonSerializer.Deserialize<Dictionary<string, string>>(firstMemoryChunk.Metadata.AdditionalMetadata);
 
         return int.Parse(metadata[ChunkSize]);
     }