NLog GoogleStackdriverTarget improve handling of System.Reflection ob…

…jects that will dump all types in the the application-assembly.

apis/Google.Cloud.Logging.NLog/Google.Cloud.Logging.NLog.Tests/GoogleStackdriverTargetTest.cs

@@ -349,6 +349,26 @@ public async Task SingleLogEntryWithJsonProperties()
             Assert.Equal("Ocean", properties.Fields["PlanetType"].StringValue);
         }
 
+        [Fact]
+        public async Task SingleLogEntryWithBadJsonProperty()
+        {
+            var uploadedEntries = await RunTestWorkingServer(
+                googleTarget =>
+                {
+                    LogManager.GetLogger("testlogger").Info("Hello {BadBoy}", new BadObject());
+                    return Task.FromResult(0);
+                }, includeEventProperties: true, configFn: googleTarget => googleTarget.SendJsonPayload = true);
+            Assert.Single(uploadedEntries);
+            var entry0 = uploadedEntries[0];
+            Assert.Equal("", entry0.TextPayload?.Trim() ?? "");
+            Assert.Equal("Hello BadObject", entry0.JsonPayload.Fields["message"].StringValue);
+
+            var properties = entry0.JsonPayload.Fields["properties"].StructValue;
+
+            Assert.Equal(1, properties.Fields.Count);
+            Assert.StartsWith("Google.Cloud.Logging.NLog.Tests", properties.Fields["BadBoy"].StructValue.Fields["Assembly"].StringValue);
+        }
+
         [Fact]
         public async Task SingleLogEntryWithJsonCollectionProperties()
         {
@@ -590,5 +610,22 @@ public async Task GaePlatform_NoConfiguredProjectId()
             // the monitored resource is at.
             Assert.Equal("gae_project_id", uploadedEntries[0].LogNameAsLogName.ProjectId);
         }
+
+        private class BadObject
+        {
+            public System.Collections.Generic.List<object> BadList { get; } = new System.Collections.Generic.List<object>();
+
+            public System.Reflection.Assembly Assembly => typeof(BadObject).Assembly;
+
+            public BadObject()
+            {
+                BadList.Add(this);
+            }
+
+            public override string ToString()
+            {
+                return nameof(BadObject);
+            }
+        }
     }
 }

apis/Google.Cloud.Logging.NLog/Google.Cloud.Logging.NLog/GoogleStackdriverTarget.cs

@@ -136,6 +136,9 @@ protected override void InitializeTarget()
                 ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore
             };
             jsonSettings.Converters.Add(new Newtonsoft.Json.Converters.StringEnumConverter());
+            jsonSettings.Converters.Add(new ToStringJsonConverter(typeof(MethodInfo)));
+            jsonSettings.Converters.Add(new ToStringJsonConverter(typeof(Assembly)));
+            jsonSettings.Converters.Add(new ToStringJsonConverter(typeof(Module)));
             jsonSettings.Error = (sender, args) =>
             {
                 // Serialization of properties that throws exceptions should not break everything

apis/Google.Cloud.Logging.NLog/Google.Cloud.Logging.NLog/ToStringJsonConverter.cs

@@ -0,0 +1,57 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System;
+using Newtonsoft.Json;
+
+namespace Google.Cloud.Logging.NLog
+{
+    internal sealed class ToStringJsonConverter : JsonConverter
+    {
+        private readonly System.Type _type;
+
+        /// <inheritdoc />
+        public override bool CanRead { get; } = false;
+
+        public ToStringJsonConverter(System.Type type)
+        {
+            _type = type;
+        }
+
+        /// <inheritdoc />
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            if (value == null)
+            {
+                writer.WriteNull();
+            }
+            else
+            {
+                writer.WriteValue(value.ToString());
+            }
+        }
+
+        /// <inheritdoc />
+        public override object ReadJson(JsonReader reader, System.Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            throw new NotSupportedException("Only serialization is supported");
+        }
+
+        /// <inheritdoc />
+        public override bool CanConvert(System.Type objectType)
+        {
+            return _type.IsAssignableFrom(objectType);
+        }
+    }
+}