Fix for issue 20 (#21)

* fix: ensure ISensitiveDataFilter are always registered

* chore: minor cleanup

src/ApplicationInsightsRequestLogging/BodyLoggerMiddleware.cs

@@ -17,7 +17,7 @@ public BodyLoggerMiddleware(IOptions<BodyLoggerOptions> options, IBodyReader bod
             _options = options.Value ?? throw new ArgumentNullException(nameof(options));
             _bodyReader = bodyReader ?? throw new ArgumentNullException(nameof(bodyReader));
             _telemetryWriter = telemetryWriter ?? throw new ArgumentNullException(nameof(telemetryWriter));
-            _sensitiveDataFilter = sensitiveDataFilter ?? throw new ArgumentNullException(nameof(telemetryWriter));
+            _sensitiveDataFilter = sensitiveDataFilter ?? throw new ArgumentNullException(nameof(sensitiveDataFilter));
         }
 
         public async Task InvokeAsync(HttpContext context, RequestDelegate next)

src/ApplicationInsightsRequestLogging/Extensions/ServiceCollectionExtensions.cs

@@ -34,15 +34,15 @@ private static void AddBodyLogger(IServiceCollection services, Action<BodyLogger
         {
             AddBodyLogger(services);
             services.Configure(setupAction);
-            services.AddTransient<ISensitiveDataFilter, SensitiveDataFilter>();
         }
-        
+
         private static void AddBodyLogger(IServiceCollection services)
         {
             services.AddScoped<BodyLoggerMiddleware>();
             services.AddScoped<IBodyReader, BodyReader>();
             services.AddScoped<ITelemetryWriter, TelemetryWriter>();
             services.AddSingleton<ITelemetryInitializer, ClientIpInitializer>();
+            services.AddTransient<ISensitiveDataFilter, SensitiveDataFilter>();
         }
     }
 }

src/ApplicationInsightsRequestLogging/Filters/SensitiveDataFilter.cs

@@ -11,7 +11,7 @@ public class SensitiveDataFilter : ISensitiveDataFilter
     {
         private const string SensitiveValueMask = "***MASKED***";
 
-        public readonly HashSet<string> _sensitiveDataPropertyKeys;
+        private readonly HashSet<string> _sensitiveDataPropertyKeys;
         private readonly IEnumerable<string> _regexesForSensitiveValues;