chore: update signing lib and pass body as byte[] (#286)

Author: tl-Roberto-Mancinelli

src/TrueLayer/ApiClient.cs

@@ -4,7 +4,6 @@
 using System.Net;
 using System.Net.Http;
 using System.Net.Http.Headers;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Net.Mime;
@@ -200,12 +199,14 @@ private Task<HttpResponseMessage> SendJsonRequestAsync(
 
             if (request is { })
             {
-                // Only serialize to string if signing is required,
-                string json = JsonSerializer.Serialize(request, request.GetType(), SerializerOptions.Default);
+                byte[] jsonBytes = JsonSerializer.SerializeToUtf8Bytes(request, request.GetType(), SerializerOptions.Default);
 
-                signer.Body(json);
+                signer.Body(jsonBytes);
 
-                httpContent = new StringContent(json, Encoding.UTF8, MediaTypeNames.Application.Json);
+                httpContent = new ByteArrayContent(jsonBytes)
+                {
+                    Headers = { ContentType = new MediaTypeHeaderValue(MediaTypeNames.Application.Json) }
+                };
             }
 
             if (!string.IsNullOrWhiteSpace(idempotencyKey))

src/TrueLayer/TrueLayer.csproj

@@ -33,7 +33,7 @@
         <PackageReference Include="Microsoft.Extensions.Http" Version="10.0.0"/>
         <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="10.0.0"/>
         <PackageReference Include="OneOf" Version="3.0.271"/>
-        <PackageReference Include="TrueLayer.Signing" Version="0.2.2" />
+        <PackageReference Include="TrueLayer.Signing" Version="0.2.4" />
 
         <!-- Source Link support for GitHub -->
         <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All"/>