allow nil/unversioned ramping version if current version is already nil/unversioned and ramp percentage is 0

go.mod

@@ -60,7 +60,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.34.0
 	go.opentelemetry.io/otel/sdk/metric v1.34.0
 	go.opentelemetry.io/otel/trace v1.34.0
-	go.temporal.io/api v1.52.1-0.20250827195718-be47585d2457
+	go.temporal.io/api v1.52.1-0.20250904205541-d426aad53c4d
 	go.temporal.io/sdk v1.35.0
 	go.uber.org/automaxprocs v1.6.0
 	go.uber.org/fx v1.23.0

go.sum

@@ -399,8 +399,8 @@ go.opentelemetry.io/otel/trace v1.34.0 h1:+ouXS2V8Rd4hp4580a8q23bg0azF2nI8cqLYnC
 go.opentelemetry.io/otel/trace v1.34.0/go.mod h1:Svm7lSjQD7kG7KJ/MUHPVXSDGz2OX4h0M2jHBhmSfRE=
 go.opentelemetry.io/proto/otlp v1.5.0 h1:xJvq7gMzB31/d406fB8U5CBdyQGw4P399D1aQWU/3i4=
 go.opentelemetry.io/proto/otlp v1.5.0/go.mod h1:keN8WnHxOy8PG0rQZjJJ5A2ebUoafqWp0eVQ4yIXvJ4=
-go.temporal.io/api v1.52.1-0.20250827195718-be47585d2457 h1:Zj4wdx4kNN/9TeFxWNiWaqdMOVExh4C3KBu0WcDnI4s=
-go.temporal.io/api v1.52.1-0.20250827195718-be47585d2457/go.mod h1:iaxoP/9OXMJcQkETTECfwYq4cw/bj4nwov8b3ZLVnXM=
+go.temporal.io/api v1.52.1-0.20250904205541-d426aad53c4d h1:bBX8TbNXEVAS50OhN29yRydfVEr83AQ+vQDjKQkB2Fk=
+go.temporal.io/api v1.52.1-0.20250904205541-d426aad53c4d/go.mod h1:iaxoP/9OXMJcQkETTECfwYq4cw/bj4nwov8b3ZLVnXM=
 go.temporal.io/sdk v1.35.0 h1:lRNAQ5As9rLgYa7HBvnmKyzxLcdElTuoFJ0FXM/AsLQ=
 go.temporal.io/sdk v1.35.0/go.mod h1:1q5MuLc2MEJ4lneZTHJzpVebW2oZnyxoIOWX3oFVebw=
 go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=

service/worker/workerdeployment/replaytester/generate_history.sh

@@ -33,7 +33,13 @@ temporal operator namespace create default
 
 # Run the worker which shall start the deployment entity workflows....
 echo "Running the Go program..."
-go run "$(dirname "$0")/worker/worker.go"
+
+if ! go run "$(dirname "$0")/worker/worker.go"; then
+  echo "Go program exited with an error. Exiting bash script." >&2
+  exit 1
+fi
+
+echo "Go program completed successfully."
 
 echo "Waiting 5 seconds for all workflows to show up in visibility..."
 sleep 5

service/worker/workerdeployment/replaytester/testdata/run_1757018813/expected_counts.txt

@@ -0,0 +1,6 @@
+# Expected workflow counts for replay testing
+# Generated by generate_history.sh on Thu Sep  4 13:46:54 PDT 2025
+EXPECTED_DEPLOYMENT_WORKFLOWS=12
+EXPECTED_VERSION_WORKFLOWS=14
+ACTUAL_DEPLOYMENT_WORKFLOWS=12
+ACTUAL_VERSION_WORKFLOWS=14

service/worker/workerdeployment/replaytester/worker/worker.go

@@ -92,16 +92,15 @@ func main() {
 	}
 	verifyDeployment(dHandle, "", build1, 1, client.WorkerDeploymentVersionDrainageStatusUnspecified)
 
-	// Set the ramp percent to 0
-	// TODO(carlydf): Once we allow it, test setting ramping version to nil while current version is also nil
+	// Unset the ramping version
 	_, err = dHandle.SetRampingVersion(context.Background(), client.WorkerDeploymentSetRampingVersionOptions{
-		BuildID:    build1,
+		BuildID:    "",
 		Percentage: 0,
 	})
 	if err != nil {
 		log.Fatalln("Unable to set ramping version to zero", err)
 	}
-	verifyDeployment(dHandle, "", build1, 0, client.WorkerDeploymentVersionDrainageStatusUnspecified)
+	verifyDeployment(dHandle, "", "", 0, client.WorkerDeploymentVersionDrainageStatusDraining)
 
 	// Set current version to 1.0
 	_, err = dHandle.SetCurrentVersion(context.Background(), client.WorkerDeploymentSetCurrentVersionOptions{

service/worker/workerdeployment/workflow.go

@@ -397,6 +397,10 @@ func (d *WorkflowRunner) handleDeleteDeployment(ctx workflow.Context) error {
 	return nil
 }
 
+func (d *WorkflowRunner) rampingVersionStringUnversioned(s string) bool {
+	return s == worker_versioning.UnversionedVersionId || s == ""
+}
+
 func (d *WorkflowRunner) validateStateBeforeAcceptingRampingUpdate(args *deploymentspb.SetRampingVersionArgs) error {
 	//nolint:staticcheck // SA1019: worker versioning v0.31
 	if args.Version == d.State.GetRoutingConfig().GetRampingVersion() &&
@@ -409,7 +413,8 @@ func (d *WorkflowRunner) validateStateBeforeAcceptingRampingUpdate(args *deploym
 		return temporal.NewApplicationError("conflict token mismatch", errFailedPrecondition)
 	}
 	//nolint:staticcheck // SA1019: worker versioning v0.31
-	if args.Version == d.State.GetRoutingConfig().GetCurrentVersion() {
+	if args.Version == d.State.GetRoutingConfig().GetCurrentVersion() &&
+		!(args.Version == worker_versioning.UnversionedVersionId && args.Percentage == 0) {
 		d.logger.Info("version can't be set to ramping since it is already current")
 		return temporal.NewApplicationError(fmt.Sprintf("requested ramping version %s is already current", args.Version), errFailedPrecondition)
 	}
@@ -492,8 +497,7 @@ func (d *WorkflowRunner) handleSetRampingVersion(ctx workflow.Context, args *dep
 			RampPercentage:    0,   // remove ramp
 		}
 
-		// TODO (Shivam): remove the empty string check once canary stops flaking out
-		if prevRampingVersion != worker_versioning.UnversionedVersionId && prevRampingVersion != "" {
+		if !d.rampingVersionStringUnversioned(prevRampingVersion) {
 			if _, err := d.syncVersion(ctx, prevRampingVersion, unsetRampUpdateArgs, false); err != nil {
 				return nil, err
 			}
@@ -542,8 +546,7 @@ func (d *WorkflowRunner) handleSetRampingVersion(ctx workflow.Context, args *dep
 			RampingSinceTime:  rampingSinceTime,
 			RampPercentage:    args.Percentage,
 		}
-		// TODO (Shivam): remove the empty string check once canary stops flaking out
-		if newRampingVersion != worker_versioning.UnversionedVersionId && newRampingVersion != "" {
+		if !d.rampingVersionStringUnversioned(newRampingVersion) {
 			if _, err := d.syncVersion(ctx, newRampingVersion, setRampUpdateArgs, true); err != nil {
 				return nil, err
 			}
@@ -560,8 +563,7 @@ func (d *WorkflowRunner) handleSetRampingVersion(ctx workflow.Context, args *dep
 				RampingSinceTime:  nil, // remove ramp
 				RampPercentage:    0,   // remove ramp
 			}
-			// TODO (Shivam): remove the empty string check once canary stops flaking out
-			if prevRampingVersion != worker_versioning.UnversionedVersionId && prevRampingVersion != "" {
+			if !d.rampingVersionStringUnversioned(prevRampingVersion) {
 				if _, err := d.syncVersion(ctx, prevRampingVersion, unsetRampUpdateArgs, false); err != nil {
 					return nil, err
 				}
@@ -954,14 +956,22 @@ func (d *WorkflowRunner) syncVersion(ctx workflow.Context, targetVersion string,
 func (d *WorkflowRunner) syncUnversionedRamp(ctx workflow.Context, versionUpdateArgs *deploymentspb.SyncVersionStateUpdateArgs) error {
 	activityCtx := workflow.WithActivityOptions(ctx, defaultActivityOptions)
 
-	// DescribeVersion activity to get all the task queues in the current version
+	// DescribeVersion activity to get all the task queues in the current version, or the ramping version if current is nil
+	version := d.State.RoutingConfig.CurrentVersion //nolint:staticcheck // SA1019: worker versioning v0.31
+	if version == worker_versioning.UnversionedVersionId {
+		version = d.State.RoutingConfig.RampingVersion //nolint:staticcheck // SA1019: worker versioning v0.31
+	}
+
+	if d.rampingVersionStringUnversioned(version) {
+		return nil
+	}
+
 	var res deploymentspb.DescribeVersionFromWorkerDeploymentActivityResult
 	err := workflow.ExecuteActivity(
 		activityCtx,
 		d.a.DescribeVersionFromWorkerDeployment,
 		&deploymentspb.DescribeVersionFromWorkerDeploymentActivityArgs{
-			Version: d.State.RoutingConfig.CurrentVersion, //nolint:staticcheck // SA1019: worker versioning v0.31
-
+			Version: version,
 		}).Get(ctx, &res)
 	if err != nil {
 		return err

tests/worker_deployment_test.go

@@ -967,6 +967,29 @@ func (s *WorkerDeploymentSuite) TestSetWorkerDeploymentRampingVersion_Invalid_Se
 	})
 }
 
+func (s *WorkerDeploymentSuite) TestSetWorkerDeploymentRampingVersion_Valid_SetNilCurrent_To_Ramping() {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+
+	tv := testvars.New(s).WithBuildIDNumber(1)
+	s.startVersionWorkflow(ctx, tv)
+
+	// set ramping version to unversioned will change the modifier identity, so it's not a no-op
+	s.setAndVerifyRampingVersion(ctx, tv, true, 0, false, "", &workflowservice.SetWorkerDeploymentRampingVersionResponse{})
+
+	// set a non-nil ramping version so that we can unset it in the next step
+	s.setAndVerifyRampingVersion(ctx, tv, false, 5, false, "", &workflowservice.SetWorkerDeploymentRampingVersionResponse{
+		PreviousVersion: worker_versioning.UnversionedVersionId,
+	})
+
+	// should be able to unset ramping version while current version is nil with no error
+	s.setAndVerifyRampingVersion(ctx, tv, true, 0, true, "", &workflowservice.SetWorkerDeploymentRampingVersionResponse{
+		PreviousVersion:           tv.DeploymentVersionString(), //nolint:staticcheck // SA1019: worker versioning v0.31
+		PreviousDeploymentVersion: tv.ExternalDeploymentVersion(),
+		PreviousPercentage:        5,
+	})
+}
+
 func (s *WorkerDeploymentSuite) TestSetWorkerDeploymentRampingVersion_ModifyExistingRampVersionPercentage() {
 	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
 	defer cancel()
@@ -1140,7 +1163,7 @@ func (s *WorkerDeploymentSuite) TestSetWorkerDeploymentRampingVersion_WithCurren
 			Name:       tv.DeploymentSeries(),
 			CreateTime: versionCreateTime,
 			RoutingConfig: &deploymentpb.RoutingConfig{
-				RampingVersion:                      "",
+				RampingVersion:                      worker_versioning.UnversionedVersionId, //nolint:staticcheck // SA1019: worker versioning v0.31
 				RampingVersionPercentage:            0,
 				RampingVersionChangedTime:           unsetRampingUpdateTime,
 				RampingVersionPercentageChangedTime: unsetRampingUpdateTime,
@@ -2970,7 +2993,7 @@ func (s *WorkerDeploymentSuite) setAndVerifyRampingVersionUnversionedOption(
 		version = worker_versioning.UnversionedVersionId
 	}
 	if unset {
-		version = ""
+		version = worker_versioning.UnversionedVersionId
 		percentage = 0
 	}
 	if !allowNoPollers && ensureSystemWorkflowsExist {