feat!: remove add_observer() and short registry names (deprecated since v2.x)

- Remove `add_observer()` method (deprecated v2.3.2, use `add_listener()`)
- Remove short name registration in registry (deprecated v0.8, use fully qualified names)
- Update release notes and upgrade guide accordingly

Author: fgmacedo

docs/releases/3.0.0.md

@@ -468,10 +468,9 @@ def on_validate(self, previous_configuration):
 ```
 
 
-### `add_observer()` renamed to `add_listener()`
+### `add_observer()` removed
 
-The method `add_observer` has been renamed to `add_listener`. The old name still works but emits
-a `DeprecationWarning`.
+The method `add_observer`, deprecated since v2.3.2, has been removed. Use `add_listener` instead.
 
 
 ### `TransitionNotAllowed` exception changes

docs/releases/upgrade_2x_to_3.md

@@ -159,8 +159,7 @@ while not sm.is_terminated:
 
 ## Replace `add_observer()` with `add_listener()`
 
-The method `add_observer` has been renamed to `add_listener`. The old name still works but emits
-a `DeprecationWarning`.
+The method `add_observer` has been removed in v3.0. Use `add_listener` instead.
 
 **Before (2.x):**
 

statemachine/registry.py

@@ -1,5 +1,3 @@
-import warnings
-
 from .utils import qualname
 
 try:
@@ -16,18 +14,11 @@ def autodiscover_modules(module_name: str):
 
 def register(cls):
     _REGISTRY[qualname(cls)] = cls
-    _REGISTRY[cls.__name__] = cls
     return cls
 
 
 def get_machine_cls(name):
     init_registry()
-    if "." not in name:
-        warnings.warn(
-            """Use fully qualified names (<module>.<class>) for state machine mixins.""",
-            DeprecationWarning,
-            stacklevel=2,
-        )
     return _REGISTRY[name]
 
 

statemachine/statemachine.py

@@ -243,15 +243,6 @@ def _register_callbacks(self, listeners: List[object]):
 
         self._callbacks.async_or_sync()
 
-    def add_observer(self, *observers):
-        """Add a listener."""
-        warnings.warn(
-            """Method `add_observer` has been renamed to `add_listener`.""",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return self.add_listener(*observers)
-
     def add_listener(self, *listeners):
         """Add a listener.
 

tests/test_listener.py

@@ -1,4 +1,3 @@
-import pytest
 from statemachine.state import State
 from statemachine.statemachine import StateMachine
 
@@ -57,30 +56,6 @@ def on_enter_state(self, target, event):
         captured = capsys.readouterr()
         assert captured.out == EXPECTED_LOG_CREATION
 
-    def test_deprecated_api(self, campaign_machine, capsys):
-        class LogObserver:
-            def __init__(self, name):
-                self.name = name
-
-            def on_transition(self, event, state, target):
-                print(f"{self.name} on: {state.id}--({event})-->{target.id}")
-
-            def on_enter_state(self, target, event):
-                print(f"{self.name} enter: {target.id} from {event}")
-
-        sm = campaign_machine()
-
-        with pytest.warns(
-            DeprecationWarning, match="Method `add_observer` has been renamed to `add_listener`."
-        ):
-            sm.add_observer(LogObserver("Frodo"))
-
-        sm.add_job()
-        sm.produce()
-
-        captured = capsys.readouterr()
-        assert captured.out == EXPECTED_LOG_ADD
-
 
 def test_regression_456():
     class TestListener:

tests/test_registry.py

@@ -25,11 +25,8 @@ class CampaignMachine(StateMachine):
         add_job = draft.to(draft) | producing.to(producing)
         produce = draft.to(producing)
 
-    assert "CampaignMachine" in registry._REGISTRY
     assert registry.get_machine_cls("tests.test_registry.CampaignMachine") == CampaignMachine
-
-    with pytest.warns(DeprecationWarning, match="fully qualified names"):
-        assert registry.get_machine_cls("CampaignMachine") == CampaignMachine
+    assert "CampaignMachine" not in registry._REGISTRY
 
 
 def test_load_modules_should_call_autodiscover_modules(django_autodiscover_modules):