Partial fix for #399 - track .Close() where possible

Okay so...we can't fix this completely. It has to be a best effort. The problem here is: not everything is going to call .Close(). The main usage case here is a DbDataReader passed a CommandBehavior.CloseConnection. It will call .Close() *on its expected type*, e.g. a SqlConnection. This will not be triggering the .Close() wrapper introduced here.

Everywhere else we do call .Close() explicitly will work fine, but even things like Dapper's .Query() won't show a .Close() in the profiler customer timings if using a data reader with close-on-finish behavior behind the scenes.

Author: Nick Craver

src/MiniProfiler.Shared/Data/ProfiledDbConnection.cs

@@ -89,7 +89,20 @@ public override string ConnectionString
         /// Closes the connection to the database.
         /// This is the preferred method of closing any open connection.
         /// </summary>
-        public override void Close() => _connection.Close();
+        public override void Close()
+        {
+            var miniProfiler = _profiler as MiniProfiler;
+            if (miniProfiler == null || !miniProfiler.IsActive || miniProfiler.Options?.TrackConnectionOpenClose == false)
+            {
+                _connection.Close();
+                return;
+            }
+
+            using (miniProfiler.CustomTiming("sql", "Connection Close()", nameof(Close)))
+            {
+                _connection.Close();
+            }
+        }
 
         /// <summary>
         /// Opens a database connection with the settings specified by the <see cref="ConnectionString"/>.
@@ -137,7 +150,7 @@ protected override DbTransaction BeginDbTransaction(IsolationLevel isolationLeve
         {
             return new ProfiledDbTransaction(_connection.BeginTransaction(isolationLevel), this);
         }
-        
+
         /// <summary>
         /// Creates and returns a <see cref="DbCommand"/> object associated with the current connection.
         /// </summary>

tests/MiniProfiler.Tests/DbProfilerTests.cs

@@ -265,7 +265,24 @@ public void TrackingOptions(bool track)
             const string cmdString = "Select 1";
             GetUnopenedConnection(profiler).Query(cmdString);
 
-            CheckConnectionTracking(track, profiler, cmdString, false);
+            CheckConnectionTracking(track, profiler, cmdString, false, false);
+        }
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void TrackingOptionsExplicitClose(bool track)
+        {
+            var options = new MiniProfilerTestOptions { TrackConnectionOpenClose = track };
+            var profiler = options.StartProfiler("Tracking: " + track);
+
+            const string cmdString = "Select 1";
+            var conn = GetUnopenedConnection(profiler);
+            conn.Open();
+            conn.Query(cmdString);
+            conn.Close();
+
+            CheckConnectionTracking(track, profiler, cmdString, false, true);
         }
 
         [Theory]
@@ -279,7 +296,7 @@ public async Task TrackingOptionsAsync(bool track)
             const string cmdString = "Select 1";
             await GetUnopenedConnection(profiler).QueryAsync(cmdString).ConfigureAwait(false);
 
-            CheckConnectionTracking(track, profiler, cmdString, true);
+            CheckConnectionTracking(track, profiler, cmdString, true, true);
         }
 
         [Fact]
@@ -292,7 +309,7 @@ public void ShimProfiler()
             const string cmdString = "Select 1";
             GetUnopenedConnection(currentDbProfiler).Query(cmdString);
 
-            CheckConnectionTracking(false, profiler, cmdString, false);
+            CheckConnectionTracking(false, profiler, cmdString, false, false);
         }
 
         private class CurrentDbProfiler : IDbProfiler
@@ -314,7 +331,7 @@ public void OnError(IDbCommand profiledDbCommand, SqlExecuteType executeType, Ex
             public void ReaderFinish(IDataReader reader) => GetProfiler()?.ReaderFinish(reader);
         }
 
-        private void CheckConnectionTracking(bool track, MiniProfiler profiler, string command, bool async)
+        private void CheckConnectionTracking(bool track, MiniProfiler profiler, string command, bool async, bool expectClose)
         {
             Assert.NotNull(profiler.Root.CustomTimings);
             Assert.Single(profiler.Root.CustomTimings);
@@ -323,9 +340,13 @@ private void CheckConnectionTracking(bool track, MiniProfiler profiler, string c
 
             if (track)
             {
-                Assert.Equal(2, sqlTimings.Count);
+                Assert.Equal(expectClose ? 3 : 2, sqlTimings.Count);
                 Assert.Equal(async ? "Connection OpenAsync()" : "Connection Open()", sqlTimings[0].CommandString);
                 Assert.Equal(command, sqlTimings[1].CommandString);
+                if (expectClose)
+                {
+                    Assert.Equal("Connection Close()", sqlTimings[2].CommandString);
+                }
             }
             else
             {