func TestMachineTransition(t *testing.T) {
rules := fsm.Ruleset{}
rules.AddTransition(fsm.T{"pending", "started"})
rules.AddTransition(fsm.T{"started", "finished"})
some_thing := Thing{State: "pending"}
the_machine := fsm.New(fsm.WithRules(rules), fsm.WithSubject(&some_thing))
var err error
// should not be able to transition to the current state
err = the_machine.Transition("pending")
st.Expect(t, err, fsm.InvalidTransition)
st.Expect(t, some_thing.State, fsm.State("pending"))
// should not be able to skip states
err = the_machine.Transition("finished")
st.Expect(t, err, fsm.InvalidTransition)
st.Expect(t, some_thing.State, fsm.State("pending"))
// should be able to transition to the next valid state
err = the_machine.Transition("started")
st.Expect(t, err, nil)
st.Expect(t, some_thing.State, fsm.State("started"))
}
func BenchmarkRulesetTransitionInvalid(b *testing.B) {
// This should be incredibly fast, since fsm.T{"pending", "finished"}
// doesn't exist in the Ruleset. We expect some small overhead from creating
// the transition to check the internal map, but otherwise, we should be
// bumping up against the speed of a map lookup itself.
rules := fsm.Ruleset{}
rules.AddTransition(fsm.T{"pending", "started"})
rules.AddTransition(fsm.T{"started", "finished"})
some_thing := &Thing{State: "pending"}
b.ResetTimer()
for i := 0; i < b.N; i++ {
rules.Permitted(some_thing, "finished")
}
}
func BenchmarkRulesetTransitionPermitted(b *testing.B) {
// Permitted a transaction requires the transition to be valid and all of its
// guards to pass. Since we have to run every guard and there won't be any
// short-circuiting, this should actually be a little bit slower as a result,
// depending on the number of guards that must pass.
rules := fsm.Ruleset{}
rules.AddTransition(fsm.T{"pending", "started"})
rules.AddTransition(fsm.T{"started", "finished"})
some_thing := &Thing{State: "started"}
b.ResetTimer()
for i := 0; i < b.N; i++ {
rules.Permitted(some_thing, "finished")
}
}
func BenchmarkRulesetRuleForbids(b *testing.B) {
// Here, we explicity create a transition that is forbidden. This simulates an
// otherwise valid transition that would be denied based on a user role or the like.
// It should be slower than a standard invalid transition, since we have to
// actually execute a function to perform the check. The first guard to
// fail (returning false) will short circuit the execution, getting some some speed.
rules := fsm.Ruleset{}
rules.AddTransition(fsm.T{"pending", "started"})
rules.AddRule(fsm.T{"started", "finished"}, func(subject fsm.Stater, goal fsm.State) error {
return errors.New("Failing guard")
})
some_thing := &Thing{State: "started"}
b.ResetTimer()
for i := 0; i < b.N; i++ {
rules.Permitted(some_thing, "finished")
}
}
func BenchmarkRulesetParallelGuarding(b *testing.B) {
rules := fsm.Ruleset{}
rules.AddTransition(fsm.T{"pending", "started"})
rules.AddTransition(fsm.T{"started", "finished"})
// Add two failing rules, one very slow and the other terribly fast
rules.AddRule(fsm.T{"started", "finished"}, func(subject fsm.Stater, goal fsm.State) error {
time.Sleep(1 * time.Second)
return errors.New("Slow guard")
})
rules.AddRule(fsm.T{"started", "finished"}, func(subject fsm.Stater, goal fsm.State) error {
return errors.New("Failing guard")
})
b.ResetTimer()
for i := 0; i < b.N; i++ {
rules.Permitted(&Thing{State: "started"}, "finished")
}
}
func TestRulesetParallelGuarding(t *testing.T) {
rules := fsm.Ruleset{}
rules.AddTransition(fsm.T{"pending", "started"})
rules.AddTransition(fsm.T{"started", "finished"})
// Add two failing rules, the slow should be caught first
rules.AddRule(fsm.T{"started", "finished"}, func(subject fsm.Stater, goal fsm.State) error {
time.Sleep(1 * time.Second)
t.Error("Slow rule should have been short-circuited")
return errors.New("Slow guard")
})
rules.AddRule(fsm.T{"started", "finished"}, func(subject fsm.Stater, goal fsm.State) error {
return errors.New("Always reject guard")
})
st.Expect(t, rules.Permitted(&Thing{State: "started"}, "finished"), errors.New("Always reject guard"))
}