Intercepters: Don't return null for Async methods

Using interceptor?. pattern sent null back for Task which was being awaited.
Pattern, for async always make null check on interceptor before calling into.
For Sync methods if they are returning void or possible null then only use interceptor?.

Testing: Errors only happen when diagnosticSource enabled so that intercepter is null but we still go inside the block.
Not sure how to set it up that in tests. Submitting PR to unblock ASP.NET Core

src/EFCore.Relational/Diagnostics/RelationalLoggerExtensions.cs

@@ -78,10 +78,7 @@ public static class RelationalLoggerExtensions
                     definition,
                     diagnosticSourceEnabled);
 
-                if (interceptor != null)
-                {
-                    return interceptor.ReaderExecuting(command, eventData, null);
-                }
+                return interceptor?.ReaderExecuting(command, eventData, null);
             }
 
             return null;
@@ -127,10 +124,7 @@ public static class RelationalLoggerExtensions
                     definition,
                     diagnosticSourceEnabled);
 
-                if (interceptor != null)
-                {
-                    return interceptor.ScalarExecuting(command, eventData, null);
-                }
+                return interceptor?.ScalarExecuting(command, eventData, null);
             }
 
             return null;
@@ -176,10 +170,7 @@ public static class RelationalLoggerExtensions
                     definition,
                     diagnosticSourceEnabled);
 
-                if (interceptor != null)
-                {
-                    return interceptor.NonQueryExecuting(command, eventData, null);
-                }
+                return interceptor?.NonQueryExecuting(command, eventData, null);
             }
 
             return null;
@@ -1006,7 +997,7 @@ private static string CommandError(EventDefinitionBase definition, EventData pay
         /// <param name="connection"> The connection. </param>
         /// <param name="startTime"> The time that the operation was started. </param>
         /// <returns> The result of execution, which may have been modified by an interceptor. </returns>
-        public static InterceptionResult?  ConnectionOpening(
+        public static InterceptionResult? ConnectionOpening(
             [NotNull] this IDiagnosticsLogger<DbLoggerCategory.Database.Connection> diagnostics,
             [NotNull] IRelationalConnection connection,
             DateTimeOffset startTime)
@@ -1029,10 +1020,7 @@ private static string CommandError(EventDefinitionBase definition, EventData pay
                     false,
                     diagnosticSourceEnabled);
 
-                if (interceptor != null)
-                {
-                    return interceptor.ConnectionOpening(connection.DbConnection, eventData, null);
-                }
+                return interceptor?.ConnectionOpening(connection.DbConnection, eventData, null);
             }
 
             return null;
@@ -1418,10 +1406,7 @@ public static void ConnectionClosed(
                     definition,
                     diagnosticSourceEnabled);
 
-                if (interceptor != null)
-                {
-                    interceptor.ConnectionClosed(connection.DbConnection, eventData);
-                }
+                interceptor?.ConnectionClosed(connection.DbConnection, eventData);
             }
         }
 
@@ -1559,10 +1544,7 @@ public static void ConnectionError(
                     definition,
                     diagnosticSourceEnabled);
 
-                if (interceptor != null)
-                {
-                    interceptor.ConnectionFailed(connection.DbConnection, eventData);
-                }
+                interceptor?.ConnectionFailed(connection.DbConnection, eventData);
             }
         }
 
@@ -1706,10 +1688,7 @@ private static string ConnectionError(EventDefinitionBase definition, EventData
                     definition,
                     diagnosticSourceEnabled);
 
-                if (interceptor != null)
-                {
-                    return interceptor.TransactionStarting(connection.DbConnection, eventData, null);
-                }
+                return interceptor?.TransactionStarting(connection.DbConnection, eventData, null);
             }
 
             return null;
@@ -1753,7 +1732,10 @@ private static string ConnectionError(EventDefinitionBase definition, EventData
                     definition,
                     diagnosticSourceEnabled);
 
-                return interceptor?.TransactionStartingAsync(connection.DbConnection, eventData, null, cancellationToken);
+                if (interceptor != null)
+                {
+                    return interceptor.TransactionStartingAsync(connection.DbConnection, eventData, null, cancellationToken);
+                }
             }
 
             return Task.FromResult<InterceptionResult<DbTransaction>?>(null);
@@ -2183,7 +2165,10 @@ private static string TransactionUsed(EventDefinitionBase definition, EventData
                     true,
                     diagnosticSourceEnabled);
 
-                return interceptor?.TransactionCommittingAsync(transaction, eventData, null, cancellationToken);
+                if (interceptor != null)
+                {
+                    return interceptor.TransactionCommittingAsync(transaction, eventData, null, cancellationToken);
+                }
             }
 
             return Task.FromResult<InterceptionResult?>(null);
@@ -2311,7 +2296,10 @@ public static Task TransactionCommittedAsync(
                     true,
                     diagnosticSourceEnabled);
 
-                return interceptor?.TransactionCommittedAsync(transaction, eventData, cancellationToken);
+                if (interceptor != null)
+                {
+                    return interceptor.TransactionCommittedAsync(transaction, eventData, cancellationToken);
+                }
             }
 
             return Task.CompletedTask;
@@ -2441,7 +2429,10 @@ public static Task TransactionRolledBackAsync(
                     true,
                     diagnosticSourceEnabled);
 
-                return interceptor?.TransactionRolledBackAsync(transaction, eventData, cancellationToken);
+                if (interceptor != null)
+                {
+                    return interceptor.TransactionRolledBackAsync(transaction, eventData, cancellationToken);
+                }
             }
 
             return Task.CompletedTask;
@@ -2568,7 +2559,10 @@ private static void LogTransactionRolledBack(
                     true,
                     diagnosticSourceEnabled);
 
-                return interceptor?.TransactionRollingBackAsync(transaction, eventData, null, cancellationToken);
+                if (interceptor != null)
+                {
+                    return interceptor.TransactionRollingBackAsync(transaction, eventData, null, cancellationToken);
+                }
             }
 
             return Task.FromResult<InterceptionResult?>(null);
@@ -2747,7 +2741,10 @@ public static Task TransactionErrorAsync(
                     true,
                     diagnosticSourceEnabled);
 
-                return interceptor?.TransactionFailedAsync(transaction, eventData, cancellationToken);
+                if (interceptor != null)
+                {
+                    return interceptor.TransactionFailedAsync(transaction, eventData, cancellationToken);
+                }
             }
 
             return Task.CompletedTask;