v0.4: Fix collision + ensure root tests run in CI

.github/workflows/ci.yml

@@ -24,5 +24,7 @@ jobs:
       - name: Install dependencies
         run: pip install pytest
 
-      - name: Run tests
+      - name: Run primitive tests
         run: python -m pytest primitives -v
+      - name: Run root tests
+        run: python -m pytest test_stop_machine.py -v

examples/demo_authority_gate.py

@@ -3,7 +3,7 @@
 import sys
 from pathlib import Path
 
-sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "primitives" / "authority-gate"))
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "primitives" / "authority-gate-v0"))
 
 from gate import Authority, AuthorityGate  # noqa: E402
 

examples/demo_stop_machine.py

@@ -2,7 +2,7 @@
 import sys
 from pathlib import Path
 
-sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "primitives" / "stop-machine"))
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "primitives" / "stop-machine-v0"))
 
 from stop_machine import Event, StopMachine  # noqa: E402
 

stop_machine.py

@@ -1,3 +1,7 @@
+# CANONICAL SOURCE: LalaSkye/constraint-workshop/stop_machine.py
+# PINNED COMMIT: 8d04cbc1e8e6576641962d5d3c866b0517ad596e
+# Semantics aligned to canonical: RED is terminal, reset() blocked from RED.
+
 """A deterministic three-state stop controller.
 
 States: GREEN -> AMBER -> RED
@@ -87,10 +91,11 @@ def transition_to(self, target: State) -> State:
         return self._state
 
     def reset(self) -> State:
-        """Reset the machine to GREEN.
-
-        Returns the new state (always GREEN).
-        """
+        """Reset the machine to GREEN. Forbidden once RED is reached."""
+        if self.is_terminal:
+            raise TerminalStateError(
+                f"Cannot reset: {self._state.value} is terminal."
+            )
         self._state = State.GREEN
         return self._state
 

test_stop_machine.py

@@ -134,21 +134,17 @@ def test_reset_from_amber():
 
 def test_reset_from_red():
     m = StopMachine(State.RED)
-    result = m.reset()
-    assert result == State.GREEN
-    assert m.state == State.GREEN
-    assert not m.is_terminal
+    with pytest.raises(TerminalStateError):
+        m.reset()
 
 
 def test_reset_then_advance():
     m = StopMachine()
     m.advance()
     m.advance()
     assert m.is_terminal
-    m.reset()
-    assert m.state == State.GREEN
-    m.advance()
-    assert m.state == State.AMBER
+    with pytest.raises(TerminalStateError):
+        m.reset()
 
 
 # --- repr ---