Preserve signal payload integer precision in workflow.SignalWorkflow

internal/signals/activities.go

@@ -2,6 +2,7 @@ package signals
 
 import (
 	"context"
+	"encoding/json"
 )
 
 type Signaler interface {
@@ -12,6 +13,6 @@ type Activities struct {
 	Signaler Signaler
 }
 
-func (a *Activities) DeliverWorkflowSignal(ctx context.Context, instanceID, signalName string, arg interface{}) error {
+func (a *Activities) DeliverWorkflowSignal(ctx context.Context, instanceID, signalName string, arg json.RawMessage) error {
 	return a.Signaler.SignalWorkflow(ctx, instanceID, signalName, arg)
 }

tester/tester_test.go

@@ -241,6 +241,55 @@ func Test_SignalSubWorkflow(t *testing.T) {
 	require.Equal(t, 42, wfR)
 }
 
+func Test_SignalWorkflow_LargeIntegerPrecision(t *testing.T) {
+	type signalPayload struct {
+		ID uint64
+	}
+
+	const (
+		receiverInstanceID = "receiver"
+		signalChannel      = "test-signal"
+		largeIntegerID     = uint64(123456789012345678)
+	)
+
+	testPayload := signalPayload{ID: largeIntegerID}
+
+	var received signalPayload
+
+	receiverWorkflow := func(ctx workflow.Context) error {
+		ch := workflow.NewSignalChannel[signalPayload](ctx, signalChannel)
+		payload, ok := ch.Receive(ctx)
+		if !ok {
+			return errors.New("signal channel unexpectedly closed")
+		}
+		received = payload
+
+		return nil
+	}
+
+	senderWorkflow := func(ctx workflow.Context) error {
+		sub := workflow.CreateSubWorkflowInstance[any](ctx, workflow.SubWorkflowOptions{
+			InstanceID: receiverInstanceID,
+		}, receiverWorkflow)
+
+		if _, err := workflow.SignalWorkflow(ctx, receiverInstanceID, signalChannel, testPayload).Get(ctx); err != nil {
+			return err
+		}
+
+		_, err := sub.Get(ctx)
+		return err
+	}
+
+	wt := NewWorkflowTester[any](senderWorkflow, WithTestTimeout(5*time.Second))
+	wt.Registry().RegisterWorkflow(receiverWorkflow)
+	wt.Execute(context.Background())
+
+	require.True(t, wt.WorkflowFinished())
+	_, err := wt.WorkflowResult()
+	require.NoError(t, err)
+	require.Equal(t, testPayload.ID, received.ID)
+}
+
 func workflowSubworkflowSignal(ctx workflow.Context) (int, error) {
 	sw := workflow.CreateSubWorkflowInstance[int](ctx, workflow.SubWorkflowOptions{
 		InstanceID: "subworkflow",

workflow/signal.go

@@ -1,9 +1,14 @@
 package workflow
 
 import (
+	"encoding/json"
+	"fmt"
+
 	"github.com/cschleiden/go-workflows/core"
+	"github.com/cschleiden/go-workflows/internal/contextvalue"
 	"github.com/cschleiden/go-workflows/internal/log"
 	"github.com/cschleiden/go-workflows/internal/signals"
+	"github.com/cschleiden/go-workflows/internal/sync"
 	"github.com/cschleiden/go-workflows/internal/workflowstate"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/trace"
@@ -24,11 +29,18 @@ func SignalWorkflow[T any](ctx Context, instanceID string, name string, arg T) F
 	)
 	defer span.End()
 
+	input, err := contextvalue.Converter(ctx).To(arg)
+	if err != nil {
+		f := sync.NewFuture[any]()
+		f.Set(nil, fmt.Errorf("converting signal input for workflow %s signal %s: %w", instanceID, name, err))
+		return f
+	}
+
 	var a *signals.Activities
 	return ExecuteActivity[any](ctx, ActivityOptions{
 		RetryOptions: RetryOptions{
 			MaxAttempts: 1,
 		},
 		Queue: core.QueueSystem,
-	}, a.DeliverWorkflowSignal, instanceID, name, arg)
+	}, a.DeliverWorkflowSignal, instanceID, name, json.RawMessage(input))
 }