use strict nondeterminism option to enable/disable new checks

internal/internal_activity.go

@@ -432,10 +432,9 @@ func deSerializeFunctionResult(f interface{}, result []byte, to interface{}, dat
 	}
 
 	// For everything we return result.
-	// TODO(remove comment):
-	// Code reaches here for 2 cases
-	// 1. activity is executed by name (not the func pointer) and it wasn't registered
-	// 2. activity is executed by func pointer and the signature indicates it doesn't/can't return data.
+	// Code reaches here for 2 cases:
+	// 	1. activity is executed by name (not the func pointer) and it wasn't registered
+	// 	2. activity is executed by func pointer and the signature indicates it doesn't/can't return data.
 	//		for example it only has one return parameter (which can only be be error).
 	return decodeArg(dataConverter, result, to)
 }

internal/internal_task_handlers.go

@@ -932,7 +932,8 @@ ProcessEvents:
 			isLast := !isInReplay && i == len(reorderedEvents)-1
 			if !skipReplayCheck {
 				isDecisionEventFn := isDecisionEvent
-				if isInReplay {
+				// when strict nondeterminism is enabled we use a different function to check for decision events during replay
+				if !w.wth.disableStrictNonDeterminism && isInReplay {
 					isDecisionEventFn = isDecisionEventForReplay
 				}
 
@@ -957,10 +958,15 @@ ProcessEvents:
 				return nil, err
 			}
 
-			// Break the event processing loop if the workflow is completed except in replay mode.
-			// In replay mode we check for nondeterminism cases and
-			// breaking the loop causes missing events in respondEvents which then causes false positives or false negatives.
-			if w.isWorkflowCompleted && !isInReplay {
+			// Break the event processing loop if either
+			//  - Workflow is completed AND strict nondeterminism checks disabled.
+			//  - Workflow is completed AND strict nondeterminism checks enabled AND NOT in replay mode.
+			// 		With strict nondeterminism checks enabled, breaking the loop early causes missing events
+			// 		in respondEvents which then causes false positives or false negatives.
+			stopProcessing := (w.isWorkflowCompleted && w.wth.disableStrictNonDeterminism) ||
+				(w.isWorkflowCompleted && !w.wth.disableStrictNonDeterminism && !isInReplay)
+
+			if stopProcessing {
 				break ProcessEvents
 			}
 		}
@@ -1046,7 +1052,7 @@ ProcessEvents:
 			// workflow timeout.
 			return nil, nonDeterministicErr
 		default:
-			panic(fmt.Sprintf("unknown mismatched workflow history policy."))
+			panic("unknown mismatched workflow history policy.")
 		}
 	}