trace2: write exit event

Write the TRACE2 exit event, which records the application exit code and
execution time in milliseconds.

Author: Lessley Dennington

src/shared/Core/ApplicationBase.cs

@@ -107,7 +107,8 @@ public Task<int> RunAsync(string[] args)
                 }
             }
 
-            return RunInternalAsync(args);
+            var exitCode = RunInternalAsync(args);
+            return exitCode;
         }
 
         protected abstract Task<int> RunInternalAsync(string[] args);

src/shared/Core/Trace2.cs

@@ -15,7 +15,8 @@ namespace GitCredentialManager;
 public enum Event
 {
     Version = 0,
-    Start = 1
+    Start = 1,
+    Exit = 2
 }
 
 /// <summary>
@@ -77,6 +78,22 @@ void WriteStart(
         long elapsedTime,
         [System.Runtime.CompilerServices.CallerFilePath] string filePath = "",
         [System.Runtime.CompilerServices.CallerLineNumber] int lineNumber = 0);
+    
+    /// <summary>
+    /// Writes exit code and execution time to trace writer.
+    /// </summary>
+    /// <param name="code">Application exit code.</param>
+    /// <param name="timeInMilliseconds">Elapsed time in milliseconds since GCM started.</param>
+    /// <param name="filePath">Path of the file this method is called from.</param>
+    /// <param name="lineNumber">Line number of file this method is called from.</param>
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1026:DefaultParametersShouldNotBeUsed")]
+    void WriteExit(
+        int code,
+        long elapsedTime,
+        [System.Runtime.CompilerServices.CallerFilePath]
+        string filePath = "",
+        [System.Runtime.CompilerServices.CallerLineNumber]
+        int lineNumber = 0);
 }
 
 public class Trace2 : DisposableObject, ITrace2
@@ -186,6 +203,26 @@ public void WriteStart(
             });
     }
 
+    public void WriteExit(
+        int code,
+        long elapsedTime,
+        string filePath = "",
+        int lineNumber = 0)
+    {
+        EnsureArgument.NotNull(code, nameof(code));
+        
+        WriteMessage(new ExitCollectorMessage()
+        {
+            Event = Event.Exit,
+            Sid = _sid,
+            Time = DateTime.UtcNow.ToString("o"),
+            File = filePath,
+            Line = lineNumber,
+            Code = code,
+            ElapsedTime = elapsedTime
+        });
+    }
+
     private void WriteMessage(CollectorMessage message)
     {
         ThrowIfDisposed();
@@ -262,3 +299,18 @@ public override string ToJson()
             new StringEnumConverter(new CamelCaseNamingStrategy()));
     }
 }
+
+public class ExitCollectorMessage : CollectorMessage
+{
+    [JsonProperty("t_abs")]
+    public long ElapsedTime { get; set; }
+
+    [JsonProperty("code")]
+    public int Code { get; set; }
+
+    public override string ToJson()
+    {
+        return JsonConvert.SerializeObject(this, 
+            new StringEnumConverter(new CamelCaseNamingStrategy()));
+    }
+}

src/shared/Git-Credential-Manager/Program.cs

@@ -79,7 +79,13 @@ public static void Main(string[] args)
                                   .ConfigureAwait(false)
                                   .GetAwaiter()
                                   .GetResult();
-
+                
+                
+                if (context.Settings.GetTrace2TracingEnabled(out string trace2Value))
+                {
+                    context.Trace2.WriteExit(exitCode,
+                        DateTimeOffset.UtcNow.ToUnixTimeSeconds() - context.Trace2.ApplicationStartTime);
+                }
                 Environment.Exit(exitCode);
             }
         }

src/shared/TestInfrastructure/Objects/NullTrace.cs

@@ -73,6 +73,12 @@ public void WriteStart(
             string filePath = "",
             int lineNumber = 0) { }
 
+        public void WriteExit(
+            int code,
+            long elapsedTime,
+            string filePath = "",
+            int lineNumber = 0) { }
+
         #endregion
 
         #region IDisposable