graphviz: quote transition labels appropriately

graph.go

@@ -195,7 +195,7 @@ func (g *graph) formatAllStateTransitions(sm *StateMachine, sr *stateRepresentat
 
 func (g *graph) formatOneTransition(sm *StateMachine, source, destination State, trigger Trigger, ltail, lhead string, actions []string, guards transitionGuard) string {
 	var sb strings.Builder
-	sb.WriteString(str(trigger, true))
+	sb.WriteString(str(trigger, false))
 	if len(actions) > 0 {
 		sb.WriteString(" / ")
 		sb.WriteString(strings.Join(actions, ", "))

graph_test.go

@@ -57,12 +57,35 @@ func withGuards() *stateless.StateMachine {
 	return sm
 }
 
+func œ(_ context.Context, args ...interface{}) bool {
+	return args[0].(int) == 2
+}
+
+func withUnicodeNames() *stateless.StateMachine {
+	sm := stateless.NewStateMachine("Ĕ")
+	sm.Configure("Ĕ").
+		Permit("◵", "ų", œ)
+	sm.Configure("ų").
+		InitialTransition("ㇴ")
+	sm.Configure("ㇴ").
+		InitialTransition("ꬠ").
+		SubstateOf("ų")
+	sm.Configure("ꬠ").
+		SubstateOf("𒀄")
+	sm.Configure("1").
+		SubstateOf("𒀄")
+	sm.Configure("2").
+		SubstateOf("1")
+	return sm
+}
+
 func TestStateMachine_ToGraph(t *testing.T) {
 	tests := []func() *stateless.StateMachine{
 		emptyWithInitial,
 		withSubstate,
 		withInitialState,
 		withGuards,
+		withUnicodeNames,
 	}
 	for _, fn := range tests {
 		name := runtime.FuncForPC(reflect.ValueOf(fn).Pointer()).Name()

testdata/golden/withUnicodeNames.dot

@@ -0,0 +1,25 @@
+digraph {
+	compound=true;
+	node [shape=Mrecord];
+	rankdir="LR";
+
+	Ĕ [label="Ĕ"];
+	subgraph cluster_ų {
+		label="ų";
+		"cluster_ų-init" [label="", shape=point];
+		ㇴ [label="ㇴ"];
+	}
+	subgraph cluster_𒀄 {
+		label="𒀄";
+		ꬠ [label="ꬠ"];
+		subgraph "cluster_1" {
+			label="1";
+			2 [label="2"];
+		}
+	}
+	"cluster_ų-init" -> ꬠ [label="", lhead="cluster_ㇴ"];
+	"cluster_ㇴ-init" -> ꬠ [label=""];
+	Ĕ -> ꬠ [label="◵ [œ]", lhead="cluster_ų"];
+	init [label="", shape=point];
+	init -> Ĕ
+}