fix(rules): stabilize is a StabilizeEffect that auto-stabilizes a dying creature

2026-09-20 10:48:08 +02:00
parent a8a65b18cd
commit f7886135bd
5 changed files with 338 additions and 16 deletions
@@ -0,0 +1,256 @@
+"""Tests for the Stabilize cantrip (SRD spells/stabilize.md).
+
+Given: the Stabilize cantrip encoding an automatic stabilization of a dying
+creature as a StabilizeEffect
+When: casting on a dying ally / a conscious creature / a dead creature / a
+hostile target / the default policy choosing a spell
+Then: a dying same-side target is stabilized without a save roll (harmless,
+willing target) and stops losing hp until new damage below the stabilized hp
+resumes dying; conscious and dead targets are unaffected; a hostile target
+rolls its Will save (success negates); and default_policy never proposes the
+cantrip (no spell slot, level-0 skipped).
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from pf1e_simulator.combat import (
+    CombatantState,
+    CombatEngine,
+    _choose_spell_action,
+)
+from pf1e_simulator.dice import parse_dice
+from pf1e_simulator.grid import Grid
+from pf1e_simulator.map import MapSpec, TerrainType
+from pf1e_simulator.models import (
+    AbilityScores,
+    ACProfile,
+    AttackSpec,
+    Combatant,
+    DamageComponent,
+    Saves,
+)
+from pf1e_simulator.rng import ScriptedRng
+from pf1e_simulator.spells import StabilizeEffect, load_spell_registry
+
+_SPELLS_DIR = Path(__file__).resolve().parent.parent / "data" / "spells"
+
+
+def _make_combatant(
+    cid: str, *, casting: bool = False, spells: list[str] | None = None
+) -> Combatant:
+    attack = AttackSpec(
+        id=f"{cid}-w",
+        name="club",
+        kind="melee",
+        attack_bonus=3,
+        damage=[DamageComponent(formula=parse_dice("1d6"), types=["bludgeoning"])],
+    )
+    return Combatant(
+        id=cid,
+        name=cid,
+        level=4,
+        size="Medium",
+        abilities=AbilityScores(
+            str_score=10, dex_score=10, con_score=10,
+            int_score=18, wis_score=10, cha_score=10,
+        ),
+        hp_max=30,
+        ac=ACProfile(total=12, touch=12, flat_footed=12),
+        bab=2,
+        initiative_mod=0,
+        speed_land_ft=30,
+        saves=Saves(fort=2, ref=2, will=2),
+        attacks=[attack],
+        casting_ability="int" if casting else "wis",
+        spell_slots={1: 3} if casting else {},
+        spells=spells or [],
+    )
+
+
+def _make_engine(
+    queue: list[int],
+    *,
+    sides: dict[str, str] | None = None,
+    positions: dict[str, tuple[int, int]] | None = None,
+    combatants: list[Combatant] | None = None,
+) -> CombatEngine:
+    roster = combatants or [_make_combatant("hero")]
+    side_map = sides or {c.id: "players" for c in roster}
+    pos_map = positions or {c.id: (i, 0) for i, c in enumerate(roster)}
+    states = [
+        CombatantState(
+            combatant=c, side=side_map[c.id], pos=pos_map[c.id], hp=c.hp_max
+        )
+        for c in roster
+    ]
+    legend = {".": TerrainType(type="floor", move_cost=1)}
+    spec = MapSpec(name="test", terrain=tuple(["." * 12] * 12), legend=legend)
+    grid = Grid.from_spec(spec)
+    reg = load_spell_registry(_SPELLS_DIR)
+    return CombatEngine(ScriptedRng(queue), grid, states, spell_registry=reg)
+
+
+class TestStabilizeLoading:
+    """Given: data/spells/stabilize.json
+    When: load_spell_registry is called
+    Then: Stabilize is a StabilizeEffect cantrip (conjuration, close, Will
+    negates (harmless))."""
+
+    def test_stabilize_is_a_stabilize_effect(self) -> None:
+        reg = load_spell_registry(_SPELLS_DIR)
+        spell = reg["Stabilize"]
+        assert len(spell.effects) == 1
+        effect = spell.effects[0]
+        assert isinstance(effect, StabilizeEffect)
+        assert spell.level == 0
+        assert spell.school == "conjuration"
+        assert spell.range == "close"
+        assert spell.save == "will"
+        assert spell.harmless is True
+
+
+class TestStabilizeCasting:
+    """Given: a caster casting Stabilize
+    When: the target is dying / conscious / dead / hostile
+    Then: a dying same-side target is stabilized without a save roll
+    (harmless, willing target) and stops losing hp; conscious and dead
+    targets are unaffected; a hostile target rolls its Will save."""
+
+    def test_stabilizes_dying_ally_without_save_roll(self) -> None:
+        caster = _make_combatant("caster", casting=True)
+        target = _make_combatant("target")
+        engine = _make_engine(
+            [3],
+            sides={"caster": "players", "target": "players"},
+            positions={"caster": (0, 0), "target": (1, 0)},
+            combatants=[caster, target],
+        )
+        c, t = engine.states
+        t.hp = -5
+        engine._cast_spell(c, t, "Stabilize")
+        assert t.stabilized_hp == -5
+        # Saving Throw Will negates (harmless): a willing same-side target
+        # forgoes the save, so the cast consumes no d20 from the queue.
+        assert len(engine._rng._queue) == 1
+
+    def test_stabilized_creature_stops_losing_hp(self) -> None:
+        caster = _make_combatant("caster", casting=True)
+        target = _make_combatant("target")
+        engine = _make_engine(
+            [3],
+            sides={"caster": "players", "target": "players"},
+            positions={"caster": (0, 0), "target": (1, 0)},
+            combatants=[caster, target],
+        )
+        c, t = engine.states
+        t.hp = -5
+        engine._cast_spell(c, t, "Stabilize")
+        engine._process_dying(t)
+        # Stabilized: no Constitution check, no further hp loss.
+        assert t.hp == -5
+        assert t.stabilized_hp == -5
+        assert len(engine._rng._queue) == 1
+
+    def test_new_damage_below_stabilized_hp_resumes_dying(self) -> None:
+        caster = _make_combatant("caster", casting=True)
+        target = _make_combatant("target")
+        engine = _make_engine(
+            [3],
+            sides={"caster": "players", "target": "players"},
+            positions={"caster": (0, 0), "target": (1, 0)},
+            combatants=[caster, target],
+        )
+        c, t = engine.states
+        t.hp = -5
+        engine._cast_spell(c, t, "Stabilize")
+        t.hp = -6
+        engine._process_dying(t)
+        # New damage below the stabilized hp resumes dying: the marker is
+        # cleared and the Constitution check is rolled (d20=3 + CON(0) - 6
+        # = -3 < DC 10 -> fails, loses 1 hp).
+        assert t.stabilized_hp is None
+        assert t.hp == -7
+        assert len(engine._rng._queue) == 0
+
+    def test_no_effect_on_conscious_creature(self) -> None:
+        caster = _make_combatant("caster", casting=True)
+        target = _make_combatant("target")
+        engine = _make_engine(
+            [3],
+            sides={"caster": "players", "target": "players"},
+            positions={"caster": (0, 0), "target": (1, 0)},
+            combatants=[caster, target],
+        )
+        c, t = engine.states
+        t.hp = 5
+        engine._cast_spell(c, t, "Stabilize")
+        assert t.stabilized_hp is None
+        assert t.hp == 5
+
+    def test_no_effect_on_dead_creature(self) -> None:
+        caster = _make_combatant("caster", casting=True)
+        target = _make_combatant("target")
+        engine = _make_engine(
+            [3],
+            sides={"caster": "players", "target": "players"},
+            positions={"caster": (0, 0), "target": (1, 0)},
+            combatants=[caster, target],
+        )
+        c, t = engine.states
+        t.hp = -12  # below -CON (con 10): dead
+        engine._cast_spell(c, t, "Stabilize")
+        assert t.stabilized_hp is None
+
+    def test_hostile_target_save_failure_stabilizes(self) -> None:
+        caster = _make_combatant("caster", casting=True)
+        target = _make_combatant("target")
+        engine = _make_engine(
+            [3],
+            sides={"caster": "players", "target": "monsters"},
+            positions={"caster": (0, 0), "target": (1, 0)},
+            combatants=[caster, target],
+        )
+        c, t = engine.states
+        t.hp = -5
+        engine._cast_spell(c, t, "Stabilize")
+        # d20=3 + will 2 = 5 < DC 14 (10 + level 0 + int 4): save fails, the
+        # dying target stabilizes.
+        assert t.stabilized_hp == -5
+        assert len(engine._rng._queue) == 0
+
+    def test_hostile_target_save_success_negates(self) -> None:
+        caster = _make_combatant("caster", casting=True)
+        target = _make_combatant("target")
+        engine = _make_engine(
+            [20],
+            sides={"caster": "players", "target": "monsters"},
+            positions={"caster": (0, 0), "target": (1, 0)},
+            combatants=[caster, target],
+        )
+        c, t = engine.states
+        t.hp = -5
+        engine._cast_spell(c, t, "Stabilize")
+        # d20=20 + will 2 = 22 >= DC 14: save succeeds, the spell is negated.
+        assert t.stabilized_hp is None
+        assert len(engine._rng._queue) == 0
+
+
+class TestStabilizePolicy:
+    """Given: the default spell selection
+    When: a caster knows Stabilize (cantrip)
+    Then: _choose_spell_action never proposes it (no spell slot, level-0
+    skipped, and StabilizeEffect is neither a heal nor a buff)."""
+
+    def test_choose_spell_action_never_proposes_stabilize(self) -> None:
+        caster = _make_combatant("caster", casting=True, spells=["Stabilize"])
+        target = _make_combatant("target")
+        engine = _make_engine(
+            [3],
+            sides={"caster": "players", "target": "monsters"},
+            positions={"caster": (0, 0), "target": (5, 0)},
+            combatants=[caster, target],
+        )
+        c, t = engine.states
+        assert _choose_spell_action(engine, c, t) is None