feat(fsm): add identifier getter

Add ability to get identifier for this instance of the state machine

context.go

@@ -4,9 +4,14 @@ import "context"
 
 type Context struct {
 	ctx  context.Context
+	name interface{}
 	send func(evt interface{}) error
 }
 
+func (ctx *Context) Name() interface{} {
+	return ctx.name
+}
+
 func (ctx *Context) Context() context.Context {
 	return ctx.ctx
 }

fsm/fsm.go

@@ -249,6 +249,10 @@ func (dc fsmContext) Context() context.Context {
 	return dc.ctx.Context()
 }
 
+func (dc fsmContext) Identifier() Identifier {
+	return dc.ctx.Name()
+}
+
 func (dc fsmContext) Event(event EventName, args ...interface{}) error {
 	evt, err := dc.d.event(dc.ctx.Context(), event, nil, args...)
 	if err != nil {

fsm/types.go

@@ -9,11 +9,17 @@ import (
 // EventName is the name of an event
 type EventName string
 
+// Identifier is a unique identifier for a given statemachine instance
+type Identifier interface{}
+
 // Context provides access to the statemachine inside of a state handler
 type Context interface {
 	// Context returns the golang context for this context
 	Context() context.Context
 
+	// Identifier returns a unique identifier for this instance of a the state machine
+	Identifier() Identifier
+
 	// Event initiates a state transition with the named event.
 	//
 	// The call takes a variable number of arguments that will be passed to the

machine.go

@@ -84,7 +84,8 @@ func (fsm *StateMachine) run() {
 			}
 
 			ctx := Context{
-				ctx: context.TODO(),
+				ctx:  context.TODO(),
+				name: fsm.name,
 				send: func(evt interface{}) error {
 					return fsm.send(Event{User: evt})
 				},