Adding ability to provide cancellation reason to cancelWorkflow API (#1213)

Author: mindaugasbarcauskas

client/client.go

@@ -162,7 +162,7 @@ type (
 		//	- BadRequestError
 		//	- InternalServiceError
 		//	- WorkflowExecutionAlreadyCompletedError
-		CancelWorkflow(ctx context.Context, workflowID string, runID string) error
+		CancelWorkflow(ctx context.Context, workflowID string, runID string, opts ...internal.Option) error
 
 		// TerminateWorkflow terminates a workflow execution.
 		// workflowID is required, other parameters are optional.

internal/client.go

@@ -45,7 +45,18 @@ const (
 	QueryTypeOpenSessions string = "__open_sessions"
 )
 
+type Option interface{ private() }
+
+type cancelReason string
+
+func (cancelReason) private() {}
+
+func WithCancelReason(reason string) Option {
+	return cancelReason(reason)
+}
+
 type (
+
 	// Client is the client for starting and getting information about a workflow executions as well as
 	// completing activities asynchronously.
 	Client interface {
@@ -139,7 +150,7 @@ type (
 		//	- BadRequestError
 		//	- InternalServiceError
 		//	- WorkflowExecutionAlreadyCompletedError
-		CancelWorkflow(ctx context.Context, workflowID string, runID string) error
+		CancelWorkflow(ctx context.Context, workflowID string, runID string, opts ...Option) error
 
 		// TerminateWorkflow terminates a workflow execution.
 		// workflowID is required, other parameters are optional.

internal/internal_workflow_client.go

@@ -458,7 +458,7 @@ func (wc *workflowClient) SignalWithStartWorkflow(ctx context.Context, workflowI
 // CancelWorkflow cancels a workflow in execution.  It allows workflow to properly clean up and gracefully close.
 // workflowID is required, other parameters are optional.
 // If runID is omit, it will terminate currently running workflow (if there is one) based on the workflowID.
-func (wc *workflowClient) CancelWorkflow(ctx context.Context, workflowID string, runID string) error {
+func (wc *workflowClient) CancelWorkflow(ctx context.Context, workflowID string, runID string, opts ...Option) error {
 	request := &s.RequestCancelWorkflowExecutionRequest{
 		Domain: common.StringPtr(wc.domain),
 		WorkflowExecution: &s.WorkflowExecution{
@@ -468,6 +468,14 @@ func (wc *workflowClient) CancelWorkflow(ctx context.Context, workflowID string,
 		Identity: common.StringPtr(wc.identity),
 	}
 
+	for _, opt := range opts {
+		switch o := opt.(type) {
+		case cancelReason:
+			cause := string(o)
+			request.Cause = &cause
+		}
+	}
+
 	return backoff.Retry(ctx,
 		func() error {
 			tchCtx, cancel, opt := newChannelContext(ctx, wc.featureFlags)

internal/internal_workflow_client_test.go

@@ -1403,3 +1403,44 @@ func serializeEvents(events []*shared.HistoryEvent) *shared.DataBlob {
 		Data:         blob.Data,
 	}
 }
+
+func (s *workflowClientTestSuite) TestCancelWorkflow() {
+	s.service.EXPECT().RequestCancelWorkflowExecution(gomock.Any(), newPartialCancelRequestMatcher(common.StringPtr("testWf"), common.StringPtr("test reason")), gomock.All(gomock.Any())).Return(nil)
+
+	err := s.client.CancelWorkflow(context.Background(), "testWf", "testRun", WithCancelReason("test reason"))
+
+	s.Nil(err)
+}
+
+func (s *workflowClientTestSuite) TestCancelWorkflowBackwardsCompatible() {
+	s.service.EXPECT().RequestCancelWorkflowExecution(gomock.Any(), newPartialCancelRequestMatcher(common.StringPtr("testWf"), nil), gomock.All(gomock.Any())).Return(nil)
+
+	err := s.client.CancelWorkflow(context.Background(), "testWf", "testRun")
+
+	s.Nil(err)
+}
+
+type PartialCancelRequestMatcher struct {
+	wfId  *string
+	cause *string
+}
+
+func newPartialCancelRequestMatcher(wfId *string, cause *string) gomock.Matcher {
+	return &PartialCancelRequestMatcher{
+		wfId:  wfId,
+		cause: cause,
+	}
+}
+
+func (m *PartialCancelRequestMatcher) Matches(a interface{}) bool {
+	aEx, ok := a.(*shared.RequestCancelWorkflowExecutionRequest)
+	if !ok {
+		return false
+	}
+
+	return (aEx.Cause == m.cause || *aEx.Cause == *m.cause) && *aEx.WorkflowExecution.WorkflowId == *m.wfId
+}
+
+func (m *PartialCancelRequestMatcher) String() string {
+	return "partial cancellation request matcher matches cause and wfId fields"
+}