Wrap underlying cause for conditional update error

service/history/decision/handler.go

@@ -548,7 +548,7 @@ Update_History_Loop:
 		}
 
 		if updateErr != nil {
-			if updateErr == execution.ErrConflict {
+			if execution.IsConflictError(updateErr) {
 				handler.metricsClient.IncCounter(metrics.HistoryRespondDecisionTaskCompletedScope, metrics.ConcurrencyUpdateFailureCounter)
 				continue Update_History_Loop
 			}

service/history/execution/context.go

@@ -27,6 +27,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"testing"
 	"time"
 
 	"github.com/uber/cadence/common"
@@ -45,10 +46,29 @@ const (
 	defaultRemoteCallTimeout = 30 * time.Second
 )
 
-var (
-	// ErrConflict is exported temporarily for integration test
-	ErrConflict = errors.New("conditional update failed")
-)
+type conflictError struct {
+	Cause error
+}
+
+func (e *conflictError) Error() string {
+	return fmt.Sprintf("conditional update failed: %v", e.Cause)
+}
+
+func (e *conflictError) Unwrap() error {
+	return e.Cause
+}
+
+// NewConflictError is only public because it used in workflow/util_test.go
+// TODO: refactor those tests
+func NewConflictError(_ *testing.T, cause error) error {
+	return &conflictError{cause}
+}
+
+// IsConflictError checks whether a conflict has occurred while updating a workflow execution
+func IsConflictError(err error) bool {
+	var e *conflictError
+	return errors.As(err, &e)
+}
 
 type (
 	// Context is the processing context for all operations on workflow execution
@@ -1114,8 +1134,7 @@ func (c *contextImpl) updateWorkflowExecutionWithRetry(
 	case nil:
 		return resp, nil
 	case *persistence.ConditionFailedError:
-		// TODO get rid of ErrConflict
-		return nil, ErrConflict
+		return nil, &conflictError{err}
 	default:
 		c.logger.Error(
 			"Persistent store operation failure",
@@ -1274,6 +1293,6 @@ func (c *contextImpl) isPersistenceTimeoutError(
 	case *persistence.TimeoutError:
 		return true
 	default:
-		return err != ErrConflict
+		return !IsConflictError(err)
 	}
 }

service/history/historyEngine.go

@@ -870,7 +870,7 @@ UpdateWorkflowLoop:
 			newMutableState,
 		)
 		if updateErr != nil {
-			if updateErr == execution.ErrConflict {
+			if execution.IsConflictError(updateErr) {
 				e.metricsClient.IncCounter(metrics.HistoryStartWorkflowExecutionScope, metrics.ConcurrencyUpdateFailureCounter)
 				continue UpdateWorkflowLoop
 			}
@@ -2391,7 +2391,7 @@ func (e *historyEngineImpl) SignalWithStartWorkflowExecution(
 			// We apply the update to execution using optimistic concurrency.  If it fails due to a conflict then reload
 			// the history and try the operation again.
 			if err := wfContext.UpdateWorkflowExecutionAsActive(ctx, e.shard.GetTimeSource().Now()); err != nil {
-				if err == execution.ErrConflict {
+				if execution.IsConflictError(err) {
 					continue Just_Signal_Loop
 				}
 				return nil, err

service/history/workflow/util.go

@@ -253,7 +253,7 @@ UpdateHistoryLoop:
 		}
 
 		err = workflowContext.GetContext().UpdateWorkflowExecutionAsActive(ctx, now)
-		if err == execution.ErrConflict {
+		if execution.IsConflictError(err) {
 			if attempt != ConditionalRetryCount-1 {
 				_, err = workflowContext.ReloadMutableState(ctx)
 				if err != nil {

service/history/workflow/util_test.go

@@ -26,6 +26,7 @@ import (
 	"time"
 
 	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/require"
 
@@ -71,7 +72,7 @@ func TestUpdateHelper(t *testing.T) {
 		{
 			msg: "update workflow conflict",
 			mockSetupFn: func(mockContext *execution.MockContext, mockMutableState *execution.MockMutableState) {
-				mockContext.EXPECT().UpdateWorkflowExecutionAsActive(gomock.Any(), gomock.Any()).Return(execution.ErrConflict).Times(ConditionalRetryCount - 1)
+				mockContext.EXPECT().UpdateWorkflowExecutionAsActive(gomock.Any(), gomock.Any()).Return(execution.NewConflictError(t, assert.AnError)).Times(ConditionalRetryCount - 1)
 				mockContext.EXPECT().UpdateWorkflowExecutionAsActive(gomock.Any(), gomock.Any()).Return(nil).Times(1)
 			},
 			actionFn: func(context execution.Context, mutableState execution.MutableState) (*UpdateAction, error) {