machine/machine_test.go

// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.

package machine

import (
	"github.com/stretchr/testify/assert"
	"log"
	"testing"
)

func setupStater(initial State) Stater {
	s := New(initial)
	if s == nil {
		log.Fatal("Failed creating new Stater")
	}
	return s
}

func TestMachineStater(t *testing.T) {
	s := setupStater("disconnected")

	s.AddStates("disconnected", "start_connection", "connected")
	r := s.GetState("connected")
	if r != "connected" {
		t.Errorf("Failed checking state: %s", r)
	}
}

func TestMachineCurrentState(t *testing.T) {
	s := setupStater("disconnected")

	s.AddStates("disconnected", "start_connection", "connected")
	r := s.CurrentState()
	if r != "disconnected" {
		t.Errorf("Failed checking state: %s", r)
	}
}

func TestMachineAddTransition(t *testing.T) {
	s := setupStater("disconnected")
	s.AddStates("disconnected", "start_connection", "connected")
	s.AddTransition("connect", States("disconnected"), "start_connection")
	s.AddModel(setupModel("disconnected"))
	// worker gets a trigger message
	assert.Nil(t, s.Trigger("connect"))

	// machine generates transition event mesages
	if s.CurrentState() != "start_connection" {
		t.Errorf("State transition failed for: connect - %s", s.CurrentState())
	}
}

func TestMachineAddSubscription(t *testing.T) {
	x := setupSubscriber()
	s := setupStater("disconnected")
	s.AddStates("disconnected", "start_connection", "connected")
	s.AddTransition("connect", States("disconnected"), "start_connection")
	assert.Nil(t, s.AddSubscription("connect", x))
	s.AddModel(setupModel("disconnected"))
	assert.Nil(t, s.Trigger("connect"))
	exitMessage := <-*x.(*EventChannel)
	enterMessage := <-*x.(*EventChannel)
	if exitMessage.On == EXITSTATEEVENT && exitMessage.Source == "disconnected" {
		if enterMessage.On == ENTERSTATEEVENT && enterMessage.Dest == "start_connection" {
			return
		}
	}
	t.Errorf("Unexpected event message in state transition notification: exit: %s, enter: %s", exitMessage, enterMessage)
}