92% test coverage

.coveragerc

@@ -0,0 +1,3 @@
+[run]
+omit =
+    tests/*

src/snanosm/mealy.py

@@ -20,16 +20,12 @@ TransitionInput = TypeVar("TransitionInput", bound=Union[InputProtocol, Transiti
 
 
 class State:
-    def __init__(self, name: str, data: object) -> None:
+    def __init__(self, name: str) -> None:
         self.__name = name
-        self.__data = data
 
     def get_name(self) -> str:
         return self.__name
 
-    def get_data(self) -> object:
-        return self.__data
-
     def __str__(self) -> str:
         return f"[State {self.__name}]"
 
@@ -37,9 +33,9 @@ class State:
         return hash(self.__name)
 
 
-class Transition(Generic[Input]):
+class Transition(Generic[TransitionInput]):
     def __init__(self, transition_input: TransitionInput, origin_name: str, destination_name: str,
-                 output_function: Callable[[Self, Optional[object]], None]) -> None:
+                 output_function: Callable[[Optional[object]], None]) -> None:
         self.__transition_input = transition_input
         self.__origin_name = origin_name
         self.__destination_name = destination_name
@@ -47,7 +43,7 @@ class Transition(Generic[Input]):
         self.__output_function = output_function
 
     def execute_output(self, context):
-        self.__output_function(context, self)
+        self.__output_function(context)
 
     def get_destination_name_hash(self) -> int:
         return self.__destination_name_hash
@@ -61,17 +57,20 @@ class Transition(Generic[Input]):
 
 
 class Machine(Generic[Input]):
-    def __init__(self) -> None:
+    def __init__(self, initial_context=None) -> None:
-        self.__start_state: Optional[int] = None
+        if initial_context is None:
+            initial_context = {}
+        self.__start_state_hash: Optional[int] = None
         self.__end_states: List[int] = []
-        self.__current_state: Optional[int] = None
+        self.__current_state_hash: Optional[int] = None
         self.__states: dict[int, State] = {}
         # dict[hash_origin, dict[hash_transition_input, Transition]]
         self.__transitions: dict[int, dict[int, Transition]] = {}
-        self.__context = {}
+        self.__initial_context = initial_context
+        self.__context = initial_context
 
     def add_transition(self, transition_input: TransitionInput, origin_name: str, destination_name: str,
-                       output_function: Callable[[Self, object], None]) -> None:
+                       output_function: Callable[[Optional[object]], None]) -> None:
         ho = hash(origin_name)
         if ho not in self.__states.keys():
             raise ValueError(f"Origin state {origin_name} does not exist.")
@@ -90,14 +89,13 @@ class Machine(Generic[Input]):
         elif hi in self.__transitions[ho]:
             raise ValueError(f"Transition already exists for origin state {origin_name} and transition input {transition_input}.")
 
-    def add_state(self, state_name: str, state_data: object, is_start_state: bool = False,
+    def add_state(self, state_name: str, is_start_state: bool = False, is_end_state: bool = False) -> None:
-                  is_end_state: bool = False) -> None:
         if state_name.startswith("#"):
             raise ValueError("State names cannot start with # (reserved for special states)")
         h: int = hash(state_name)
         if is_start_state:
-            if self.__start_state is None:
+            if self.__start_state_hash is None:
-                self.__start_state = h
+                self.__start_state_hash = h
             else:
                 raise ValueError("Adding a start state when one is already set.")
         if is_end_state:
@@ -105,7 +103,7 @@ class Machine(Generic[Input]):
             self.__end_states.append(h)
         if h in self.__states.keys():
             raise ValueError(f"State {state_name} already exists.")
-        state = State(state_name, state_data)
+        state = State(state_name)
         self.__states[h] = state
 
     def get_state(self, name: str) -> Optional[State]:
@@ -113,28 +111,18 @@ class Machine(Generic[Input]):
         # KeyError if the state is not found
         return self.__states[h]
 
-    def reset(self) -> None:
-        if self.__start_state is None:
-            raise ValueError("Resetting a machine without starting state.")
-        self.__current_state = self.__start_state
-
-    def get_current_state(self) -> Optional[State]:
-        if self.__current_state is None:
-            return None # The machine has not started yet
-        return self.__states[self.__current_state]
-
     def process_input(self, i: Input) -> None:
-        if self.__start_state is None:
+        if self.__start_state_hash is None:
             raise ValueError("Processing input without a start state.")
-        if self.__current_state is None:
+        if self.__current_state_hash is None:
-            self.__current_state = self.__start_state
+            self.__current_state_hash = self.__start_state_hash
-        hs = hash(self.__current_state)
         # dict[hash_origin, dict[hash_transition_input, Transition]]
-        if hs not in self.__transitions.keys():
+        if self.__current_state_hash not in self.__transitions.keys():
             raise ValueError("Processing input for a state with no transitions.")
-        transitions = self.__transitions[hs]
+        # noinspection PyTypeChecker
+        transitions = self.__transitions[self.__current_state_hash]
         hi = hash(i)
-        transition = None
+        transition: Optional[Transition] = None
         if hi in transitions.keys():
             # Transition found: execute and move to the destination state
             transition = transitions[hi]
@@ -145,8 +133,20 @@ class Machine(Generic[Input]):
                 transition = transitions[hc]
             else:
                 raise ValueError(f"Found invalid transition while processing input {i} [{transition}].]")
+        assert transition is not None
         transition.execute_output(self.__context)
-        self.__current_state = transition.get_destination_name_hash()
+        self.__current_state_hash = transition.get_destination_name_hash()
+
+    def reset(self) -> None:
+        if self.__start_state_hash is None:
+            raise ValueError("Resetting a machine without starting state.")
+        self.__current_state_hash = self.__start_state_hash
+        self.__context = self.__initial_context
+
+    def get_current_state(self) -> Optional[State]:
+        if self.__current_state_hash is None:
+            return None # The machine has not started yet
+        return self.__states[self.__current_state_hash]
 
     def __str__(self) -> str:
         r = [f"=MACHINE=", "\tSTATES"]

test/test_mealy.py

@@ -1,21 +0,0 @@
-import unittest
-
-from src.snanosm.mealy import Machine
-
-
-class TestMachine(unittest.TestCase):
-
-    def test_init(self):
-        m = Machine()
-        self.assertIsNotNone(m)
-
-    def test_add_state_two_start_states(self):
-        m = Machine()
-        m.add_state("A", {}, True, False)
-        self.assertRaises(ValueError, m.add_state, "B", {}, True, False)
-
-    def test_add_two_end_states(self):
-        m = Machine()
-        m.add_state("A", {}, True, False)
-        m.add_state("B", {}, False, True)
-        m.add_state("C", {}, False, True)

tests/test_mealy.py

@@ -0,0 +1,236 @@
+from dataclasses import dataclass
+import unittest
+
+from snanosm.mealy import Machine, TransitionInputEnum, State, Transition
+
+
+# Any hashable and equatable object should suffice
+@dataclass(frozen=True)
+class TestTransitionObject:
+    attribute: str
+
+
+class TestMachine(unittest.TestCase):
+
+    def test_init(self):
+        m = Machine()
+        self.assertIsNotNone(m)
+
+    # ADD STATE
+
+    def test_add_state_two_start_states(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        with self.assertRaises(ValueError):
+            m.add_state("B", True, False)
+
+    def test_add_two_end_states(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_state("C", False, True)
+
+    def test_add_state_with_reserved_name(self):
+        m = Machine()
+        with self.assertRaises(ValueError):
+            m.add_state("#INVALID_STATE_NAME", True, False)
+
+    def test_add_state_with_duplicate_state_name(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        with self.assertRaises(ValueError):
+            m.add_state("A", False, True)
+
+    # GET STATE
+
+    def test_get_states(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        state = m.get_state("A")
+        self.assertIsNotNone(state)
+        assert state is not None
+        self.assertEqual(state.get_name(), "A")
+
+    # ADD TRANSITION
+
+    def test_add_transition(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_transition("X", "A", "B", lambda context: print(context))
+
+    def test_add_transition_non_existent_origin_state(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        with self.assertRaises(ValueError):
+            m.add_transition("X", "C", "B", lambda context: print(context))
+
+    def test_add_transition_non_existent_destination_state(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        with self.assertRaises(ValueError):
+            m.add_transition("X", "A", "C", lambda context: print(context))
+
+    def test_add_special_transition(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_transition(TransitionInputEnum.MATCH_REST, "A", "B", lambda context: print(context))
+
+    def test_add_several_transitions_with_same_origin(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_transition("X", "A", "B", lambda context: print("1"))
+        m.add_transition("Y", "A", "B", lambda context: print("2"))
+
+    def test_add_duplicate_transition(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_transition("X", "A", "B", lambda context: print("1"))
+        with self.assertRaises(ValueError):
+            m.add_transition("X", "A", "B", lambda context: print("2"))
+
+    # PROCESS INPUT
+
+    def test_process_input(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, False)
+        m.add_state("C", False, True)
+        m.add_transition("X", "A", "B", lambda context: print("TEST_PROCESS_INPUT: Transition 1"))
+        m.add_transition("X", "B", "C", lambda context: print("TEST_PROCESS_INPUT: Transition 2"))
+        m.process_input("X")
+        m.process_input("X")
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "C")
+
+    def test_process_input_no_start_state(self):
+        m = Machine()
+        m.add_state("A", False, False)
+        m.add_state("B", False, False)
+        m.add_transition("X", "A", "B", lambda context: print("TEST_PROCESS_INPUT_NO_START_DATE: Transition"))
+        with self.assertRaises(ValueError):
+            m.process_input("X")
+
+    def test_process_input_state_without_transitions(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_transition("X", "A", "B", lambda context: print("TEST_PROCESS_INPUT_WITHOUT_TRANSITIONS: Transition"))
+        m.process_input("X")
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "B")
+        with self.assertRaises(ValueError):
+            m.process_input("X")
+
+    def test_process_input_catch_all_transition(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_transition(TransitionInputEnum.MATCH_REST, "A", "B", lambda context: print("A -> B"))
+        m.add_transition(TransitionInputEnum.MATCH_REST, "B", "A", lambda context: print("B -> A"))
+        m.process_input("X")
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "B")
+        m.process_input(1)
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "A")
+        m.process_input(TestTransitionObject("X"))
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "B")
+
+    def test_process_input_with_objects(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, False)
+        m.add_state("C", False, True)
+        m.add_transition(TestTransitionObject("TEST_1"), "A", "B", lambda context: print("A -> B"))
+        m.add_transition(TestTransitionObject("TEST_2"), "B", "C", lambda context: print("B -> C"))
+        m.process_input(TestTransitionObject("TEST_1"))
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "B")
+        m.process_input(TestTransitionObject("TEST_2"))
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "C")
+
+    def test_process_input_invalid_transition(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_transition("X", "A", "B", lambda context: print("A -> B"))
+        with self.assertRaises(ValueError):
+            m.process_input("Y")
+
+    # GET CURRENT STATE
+    def test_get_current_state_machine_not_started(self):
+        m = Machine()
+        state = m.get_current_state()
+        self.assertIsNone(state)
+
+    def test_get_current_state_machine_started(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_transition("X", "A", "B", lambda context: print("A -> B"))
+        m.process_input("X")
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "B")
+
+    # RESET
+
+    def test_reset(self):
+        m = Machine()
+        m.add_state("A", True, False)
+        m.add_state("B", False, True)
+        m.add_transition("X", "A", "B", lambda context: print("A -> B"))
+        m.process_input("X")
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "B")
+        m.reset()
+        current_state = m.get_current_state()
+        self.assertIsNotNone(current_state)
+        assert current_state is not None
+        self.assertEqual(current_state.get_name(), "A")
+
+    def test_reset_no_start_state(self):
+        m = Machine()
+        m.add_state("A", False, False)
+        with self.assertRaises(ValueError):
+            m.reset()
+
+    # STATE
+
+    def test_state_str(self):
+        s = State("A")
+        t = str(s)
+        self.assertEqual(t, "[State A]")
+
+    # TRANSITION
+
+    def test_transition_str(self):
+        t = Transition("TEST_1", "A", "B", lambda context: print("A -> B"))
+        self.assertEqual(str(t), "[Transition (A, B, TEST_1)]")
+
+