fix

d2graph/serde.go

@@ -28,7 +28,7 @@ func DeserializeGraph(bytes []byte, g *Graph) error {
 	}
 
 	var root Object
-	convert(sg.Root, &root)
+	Convert(sg.Root, &root)
 	g.Root = &root
 	root.Graph = g
 	g.RootLevel = sg.RootLevel
@@ -38,7 +38,7 @@ func DeserializeGraph(bytes []byte, g *Graph) error {
 	var objects []*Object
 	for _, so := range sg.Objects {
 		var o Object
-		if err := convert(so, &o); err != nil {
+		if err := Convert(so, &o); err != nil {
 			return err
 		}
 		o.Graph = g
@@ -67,7 +67,7 @@ func DeserializeGraph(bytes []byte, g *Graph) error {
 	var edges []*Edge
 	for _, se := range sg.Edges {
 		var e Edge
-		if err := convert(se, &e); err != nil {
+		if err := Convert(se, &e); err != nil {
 			return err
 		}
 
@@ -108,7 +108,7 @@ func SerializeGraph(g *Graph) ([]byte, error) {
 
 	var sedges []SerializedEdge
 	for _, e := range g.Edges {
-		se, err := toSerializedEdge(e)
+		se, err := ToSerializedEdge(e)
 		if err != nil {
 			return nil, err
 		}
@@ -121,7 +121,7 @@ func SerializeGraph(g *Graph) ([]byte, error) {
 
 func toSerializedObject(o *Object) (SerializedObject, error) {
 	var so SerializedObject
-	if err := convert(o, &so); err != nil {
+	if err := Convert(o, &so); err != nil {
 		return nil, err
 	}
 
@@ -138,9 +138,9 @@ func toSerializedObject(o *Object) (SerializedObject, error) {
 	return so, nil
 }
 
-func toSerializedEdge(e *Edge) (SerializedEdge, error) {
+func ToSerializedEdge(e *Edge) (SerializedEdge, error) {
 	var se SerializedEdge
-	if err := convert(e, &se); err != nil {
+	if err := Convert(e, &se); err != nil {
 		return nil, err
 	}
 
@@ -154,7 +154,7 @@ func toSerializedEdge(e *Edge) (SerializedEdge, error) {
 	return se, nil
 }
 
-func convert[T, Q any](from T, to *Q) error {
+func Convert[T, Q any](from T, to *Q) error {
 	b, err := json.Marshal(from)
 	if err != nil {
 		return err

d2plugin/exec.go

@@ -201,3 +201,59 @@ func (p *execPlugin) PostProcess(ctx context.Context, in []byte) ([]byte, error)
 
 	return stdout, nil
 }
+
+func (p *execPlugin) RouteEdges(ctx context.Context, g *d2graph.Graph, edges []*d2graph.Edge) error {
+	ctx, cancel := timelib.WithTimeout(ctx, time.Minute*2)
+	defer cancel()
+
+	graphBytes, err := d2graph.SerializeGraph(g)
+	if err != nil {
+		return err
+	}
+
+	var g2 d2graph.Graph
+	err = d2graph.DeserializeGraph(graphBytes, &g2)
+	if err != nil {
+		return fmt.Errorf("failed to unmarshal json: %w", err)
+	}
+	g2.Edges = edges
+	graphBytes2, err := d2graph.SerializeGraph(&g2)
+	if err != nil {
+		return err
+	}
+
+	in := routeEdgesInput{
+		g:      graphBytes,
+		gedges: graphBytes2,
+	}
+
+	b, err := json.Marshal(in)
+	if err != nil {
+		return err
+	}
+
+	args := []string{"routeedges"}
+	for k, v := range p.opts {
+		args = append(args, fmt.Sprintf("--%s", k), v)
+	}
+	cmd := exec.CommandContext(ctx, p.path, args...)
+
+	buffer := bytes.Buffer{}
+	buffer.Write(b)
+	cmd.Stdin = &buffer
+
+	stdout, err := cmd.Output()
+	if err != nil {
+		ee := &exec.ExitError{}
+		if errors.As(err, &ee) && len(ee.Stderr) > 0 {
+			return fmt.Errorf("%v\nstderr:\n%s", ee, ee.Stderr)
+		}
+		return err
+	}
+	err = d2graph.DeserializeGraph(stdout, g)
+	if err != nil {
+		return fmt.Errorf("failed to unmarshal json: %w", err)
+	}
+
+	return nil
+}

d2plugin/plugin.go

@@ -85,6 +85,11 @@ type RoutingPlugin interface {
 	RouteEdges(context.Context, *d2graph.Graph, []*d2graph.Edge) error
 }
 
+type routeEdgesInput struct {
+	g      []byte
+	gedges []byte
+}
+
 // PluginInfo is the current info information of a plugin.
 // note: The two fields Type and Path are not set by the plugin
 // itself but only in ListPlugins.

d2plugin/serve.go

@@ -58,6 +58,12 @@ func Serve(p Plugin) xmain.RunFunc {
 			return layout(ctx, p, ms)
 		case "postprocess":
 			return postProcess(ctx, p, ms)
+		case "routeedges":
+			routingPlugin, ok := p.(RoutingPlugin)
+			if !ok {
+				return fmt.Errorf("plugin has routing feature but does not implement RoutingPlugin")
+			}
+			return routeEdges(ctx, routingPlugin, ms)
 		default:
 			return xmain.UsageErrorf("unrecognized command: %s", subcmd)
 		}
@@ -137,3 +143,39 @@ func postProcess(ctx context.Context, p Plugin, ms *xmain.State) error {
 	}
 	return nil
 }
+
+func routeEdges(ctx context.Context, p RoutingPlugin, ms *xmain.State) error {
+	inRaw, err := io.ReadAll(ms.Stdin)
+	if err != nil {
+		return err
+	}
+
+	in := routeEdgesInput{}
+
+	err = json.Unmarshal(inRaw, &in)
+
+	var g d2graph.Graph
+	if err := d2graph.DeserializeGraph(in.g, &g); err != nil {
+		return fmt.Errorf("failed to unmarshal input graph to graph: %s", in)
+	}
+
+	var gedges d2graph.Graph
+	if err := d2graph.DeserializeGraph(in.gedges, &gedges); err != nil {
+		return fmt.Errorf("failed to unmarshal input edges graph to graph: %s", in)
+	}
+
+	err = p.RouteEdges(ctx, &g, gedges.Edges)
+	if err != nil {
+		return err
+	}
+
+	b, err := d2graph.SerializeGraph(&g)
+	if err != nil {
+		return err
+	}
+	_, err = ms.Stdout.Write(b)
+	if err != nil {
+		return err
+	}
+	return nil
+}