feat: Support to declare States using Enum. Closes #367 #375

fgmacedo · 2023-03-15T15:40:36Z

Add support to declare States using Enum.

Given that you assign the response of States.from_enum to a class level
variable on your StateMachine you're good to go, you can use any name.
The variable will be inspected by the metaclass and the State instances
assigned to the state machine.

Enum campaign machine

A StateMachine that demonstrates using an Enum as source for States declaration.

from enum import Enum

from statemachine import StateMachine
from statemachine.states import States


class CampaignStatus(Enum):
    draft = 1
    producing = 2
    closed = 3


class CampaignMachine(StateMachine):
    "A workflow machine"

    _ = States.from_enum(
        CampaignStatus, initial=CampaignStatus.draft, final=CampaignStatus.closed
    )

    add_job = _.draft.to(_.draft) | _.producing.to(_.producing)
    produce = _.draft.to(_.producing)
    deliver = _.producing.to(_.closed)

Asserting campaign machine declaration

assert CampaignMachine.draft.initial
assert not CampaignMachine.draft.final

assert not CampaignMachine.producing.initial
assert not CampaignMachine.producing.final

assert not CampaignMachine.closed.initial
assert CampaignMachine.closed.final

Testing our campaign machine

sm = CampaignMachine()
res = sm.send("produce")

assert sm.draft.is_active is False
assert sm.producing.is_active is True
assert sm.closed.is_active is False
assert sm.current_state == sm.producing
assert sm.current_state_value == CampaignStatus.producing.value

codecov · 2023-03-15T15:42:10Z

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (2420b18) 100.00% compared to head (743e8ff) 100.00%.

Additional details and impacted files

@@            Coverage Diff            @@
##           develop      #375   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           19        20    +1     
  Lines          936       976   +40     
  Branches       154       161    +7     
=========================================
+ Hits           936       976   +40

Flag	Coverage Δ
unittests	`100.00% <100.00%> (ø)`

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
statemachine/registry.py	`100.00% <ø> (ø)`
statemachine/state.py	`100.00% <ø> (ø)`
statemachine/factory.py	`100.00% <100.00%> (ø)`
statemachine/model.py	`100.00% <100.00%> (ø)`
statemachine/statemachine.py	`100.00% <100.00%> (ø)`
statemachine/states.py	`100.00% <100.00%> (ø)`
statemachine/transition_list.py	`100.00% <100.00%> (ø)`
statemachine/utils.py	`100.00% <100.00%> (ø)`