Improve in-proc collector logs (#552)

Improve in-proc collector logs

Author: MarcoRossignoli

Documentation/Troubleshooting.md

@@ -199,4 +199,17 @@ Fire attach
 System.Diagnostics.Debugger.Launch();
 ```
 
+If you want debug in-process collector you need to set VSTEST_HOST_DEBUG(https://github.com/microsoft/vstest/issues/2158) environment variable
+```
+set VSTEST_HOST_DEBUG=1
+```
+Test host will wait for debugger
+```
+Starting test execution, please wait...
+Logging Vstest Diagnostics in file: C:\git\coverletissue\collectorlog\XUnitTestProject1\log.txt
+Host debugging is enabled. Please attach debugger to testhost process to continue.
+Process Id: 800, Name: dotnet
+```
+
 **Every time you update code and rebuild new package remember to remove local nuget cache(`RMDIR "C:\Users\[winUser]\.nuget\packages\coverlet.collector" /S /Q`) otherwise you'll load old collector code because the package version wasn't changed**
+

src/coverlet.collector/InProcDataCollection/CoverletInProcDataCollector.cs

@@ -1,9 +1,9 @@
 using System;
 using System.Reflection;
+
 using coverlet.collector.Resources;
 using Coverlet.Collector.Utilities;
 using Coverlet.Core.Instrumentation;
-using Microsoft.VisualStudio.TestPlatform.ObjectModel;
 using Microsoft.VisualStudio.TestPlatform.ObjectModel.DataCollection;
 using Microsoft.VisualStudio.TestPlatform.ObjectModel.DataCollector.InProcDataCollector;
 using Microsoft.VisualStudio.TestPlatform.ObjectModel.InProcDataCollector;
@@ -12,8 +12,12 @@ namespace Coverlet.Collector.DataCollection
 {
     public class CoverletInProcDataCollector : InProcDataCollection
     {
+        private TestPlatformEqtTrace _eqtTrace;
+
         public void Initialize(IDataCollectionSink dataCollectionSink)
         {
+            _eqtTrace = new TestPlatformEqtTrace();
+            _eqtTrace.Verbose("Initialize CoverletInProcDataCollector");
         }
 
         public void TestCaseEnd(TestCaseEndArgs testCaseEndArgs)
@@ -36,17 +40,14 @@ public void TestSessionEnd(TestSessionEndArgs testSessionEndArgs)
 
                 try
                 {
+                    _eqtTrace.Verbose($"Calling ModuleTrackerTemplate.UnloadModule for '{injectedInstrumentationClass.Assembly.FullName}'");
                     var unloadModule = injectedInstrumentationClass.GetMethod(nameof(ModuleTrackerTemplate.UnloadModule), new[] { typeof(object), typeof(EventArgs) });
                     unloadModule.Invoke(null, new[] { null, EventArgs.Empty });
+                    _eqtTrace.Verbose($"Called ModuleTrackerTemplate.UnloadModule for '{injectedInstrumentationClass.Assembly.FullName}'");
                 }
                 catch (Exception ex)
                 {
-                    // Throw any exception if unload fails
-                    if (EqtTrace.IsErrorEnabled)
-                    {
-                        EqtTrace.Error("{0}: Failed to unload module with error: {1}", CoverletConstants.InProcDataCollectorName, ex);
-                    }
-
+                    _eqtTrace.Error("{0}: Failed to unload module with error: {1}", CoverletConstants.InProcDataCollectorName, ex);
                     string errorMessage = string.Format(Resources.FailedToUnloadModule, CoverletConstants.InProcDataCollectorName);
                     throw new CoverletDataCollectorException(errorMessage, ex);
                 }
@@ -57,7 +58,7 @@ public void TestSessionStart(TestSessionStartArgs testSessionStartArgs)
         {
         }
 
-        private static Type GetInstrumentationClass(Assembly assembly)
+        private Type GetInstrumentationClass(Assembly assembly)
         {
             try
             {
@@ -74,11 +75,7 @@ private static Type GetInstrumentationClass(Assembly assembly)
             }
             catch (Exception ex)
             {
-                // Avoid crashing if reflection fails.
-                if (EqtTrace.IsWarningEnabled)
-                {
-                    EqtTrace.Warning("{0}: Failed to get Instrumentation class with error: {1}", CoverletConstants.InProcDataCollectorName, ex);
-                }
+                _eqtTrace.Warning("{0}: Failed to get Instrumentation class with error: {1}", CoverletConstants.InProcDataCollectorName, ex);
                 return null;
             }
         }

src/coverlet.collector/Utilities/TestPlatformEqtTrace.cs

@@ -39,5 +39,15 @@ public void Info(string format, params object[] args)
         {
             EqtTrace.Info($"[coverlet]{format}", args);
         }
+
+        /// <summary>
+        /// Error logger
+        /// </summary>
+        /// <param name="format">Format</param>
+        /// <param name="args">Args</param>
+        public void Error(string format, params object[] args)
+        {
+            EqtTrace.Error($"[coverlet]{format}", args);
+        }
     }
 }