From 38d90da4c5aa83575fa85628c55ab64f37fda1be Mon Sep 17 00:00:00 2001
From: Marcus Carey <mcarey@firebend.com>
Date: Wed, 17 Sep 2025 18:24:15 -0500
Subject: [PATCH] fix: refactor DefaultJsonPatchGenerator to use
 IServiceProvider for IJsonPatchWriter instantiation

---
 src/JsonPatchGenerator/DefaultJsonPatchGenerator.cs | 13 +++++++++----
 .../Extensions/ServiceCollectionExtensions.cs       |  5 +----
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/JsonPatchGenerator/DefaultJsonPatchGenerator.cs b/src/JsonPatchGenerator/DefaultJsonPatchGenerator.cs
index c020b7e..bdf4e33 100644
--- a/src/JsonPatchGenerator/DefaultJsonPatchGenerator.cs
+++ b/src/JsonPatchGenerator/DefaultJsonPatchGenerator.cs
@@ -4,6 +4,7 @@
 using Firebend.JsonPatch.Models;
 using Microsoft.AspNetCore.JsonPatch;
 using Microsoft.AspNetCore.JsonPatch.Operations;
+using Microsoft.Extensions.DependencyInjection;
 using Newtonsoft.Json;
 
 namespace Firebend.JsonPatch;
@@ -11,12 +12,15 @@ namespace Firebend.JsonPatch;
 public class DefaultJsonPatchGenerator : IJsonPatchGenerator
 {
     private readonly IJsonDiffDetector _diffDetector;
-    private readonly Func<IJsonPatchWriter> _writerFactory;
+    private readonly IServiceProvider _serviceProvider;
     private readonly IJsonDiffSettingsProvider _settings;
-    public DefaultJsonPatchGenerator(IJsonDiffDetector diffDetector, Func<IJsonPatchWriter> writerFactory, IJsonDiffSettingsProvider settings)
+
+    public DefaultJsonPatchGenerator(IJsonDiffDetector diffDetector,
+        IServiceProvider serviceProvider,
+        IJsonDiffSettingsProvider settings)
     {
         _diffDetector = diffDetector;
-        _writerFactory = writerFactory;
+        _serviceProvider = serviceProvider;
         _settings = settings;
     }
 
@@ -42,7 +46,8 @@ public JsonPatchDocument<T> Generate<T>(T original, T modified)
 
         if (!diffs.Any()) { return new(); }
 
-        var writer = _writerFactory();
+        using var scope = _serviceProvider.CreateScope();
+        var writer = scope.ServiceProvider.GetRequiredService<IJsonPatchWriter>();
 
         foreach (var jsonDiff in diffs)
         {
diff --git a/src/JsonPatchGenerator/Extensions/ServiceCollectionExtensions.cs b/src/JsonPatchGenerator/Extensions/ServiceCollectionExtensions.cs
index 1161260..ac6032f 100644
--- a/src/JsonPatchGenerator/Extensions/ServiceCollectionExtensions.cs
+++ b/src/JsonPatchGenerator/Extensions/ServiceCollectionExtensions.cs
@@ -46,10 +46,7 @@ public static IServiceCollection AddJsonPatchGenerator(this IServiceCollection c
 
         collection.TryAddSingleton<IJsonDiffSettingsProvider>(new JsonDiffSettingsProvider(settings));
         collection.TryAddTransient<IJsonPatchWriter, JsonPatchWriter>();
-        collection.TryAddTransient<IJsonPatchGenerator>(sp =>
-            new DefaultJsonPatchGenerator(sp.GetRequiredService<IJsonDiffDetector>(),
-                sp.GetRequiredService<IJsonPatchWriter>,
-                sp.GetRequiredService<IJsonDiffSettingsProvider>()));
+        collection.TryAddTransient<IJsonPatchGenerator, DefaultJsonPatchGenerator>();
         collection.TryAddTransient<IJsonDiffDetector, JsonDiffDetector>();
 
         return collection;