fix(rules): self-centered bursts for bless and bane - AreaEffect gains a data-driven 'centered_on_caster' flag (bless.json/bane.json set it per SRD bless.md '50-ft. burst, centered on the caster' and bane.md 'centered on you'); the burst origin is the caster's square regardless of the resolved target or a U7b target_pos, and with no chosen origin there is no primary save - every creature in the area rolls its own (mirror of the point-cast path); snapshot area key exposes centered_on_caster; golden transcript unchanged; +6 tests

tests/test_self_centered_burst.py

@@ -0,0 +1,133 @@
+"""Self-centered bursts: Bless and Bane originate on the CASTER.
+
+PF1e (SRD spells/bless.md): "Area: The caster and all allies within a 50-ft.
+burst, centered on the caster"; (SRD spells/bane.md): "Area: 50-ft.-radius
+burst, centered on you". The engine honors a data-driven
+``AreaEffect.centered_on_caster`` flag (set on bless.json / bane.json): the
+burst's point of origin is the caster's square regardless of the resolved
+target (or a U7b ``target_pos``), and there is no primary save - every
+creature in the area rolls its own, like the point-targeted path.
+"""
+
+from __future__ import annotations
+
+from pf1e_simulator.combat import CombatantState, CombatEngine
+from pf1e_simulator.grid import Grid
+from pf1e_simulator.map import MapSpec, TerrainType
+from pf1e_simulator.rng import ScriptedRng
+from pf1e_simulator.spells import SPELLS_DIR, AreaEffect, load_spell_registry
+from tests.test_spells import _make_caster, _make_target
+
+
+def _engine(queue: list[int], states: list[CombatantState]) -> CombatEngine:
+    legend = {".": TerrainType(type="floor", move_cost=1)}
+    spec = MapSpec(name="open", terrain=tuple(["." * 12] * 12), legend=legend)
+    return CombatEngine(
+        ScriptedRng(queue), Grid.from_spec(spec), states,
+        spell_registry=load_spell_registry(SPELLS_DIR),
+    )
+
+
+def _state(cid: str, side: str, pos: tuple[int, int], *, caster: bool = False,
+           spells: tuple[str, ...] = ()) -> CombatantState:
+    model = (
+        _make_caster(cid).model_copy(update={"spells": list(spells)})
+        if caster
+        else _make_target(cid)
+    )
+    return CombatantState(combatant=model, side=side, pos=pos, hp=model.hp_max)
+
+
+def _has_buff(state: CombatantState, spell_name: str) -> bool:
+    return any(b.source == f"spell: {spell_name}" for b in state.active_buffs)
+
+
+def _has_condition(state: CombatantState, name: str) -> bool:
+    return any(ac.condition.name == name for ac in state.active_conditions)
+
+
+def test_registry_marks_bless_and_bane_centered() -> None:
+    registry = load_spell_registry(SPELLS_DIR)
+    for name in ("Bless", "Bane"):
+        areas = [e for e in registry[name].effects if isinstance(e, AreaEffect)]
+        assert len(areas) == 1
+        assert areas[0].centered_on_caster is True
+    fireball = registry["Fireball"].effects[0]
+    assert isinstance(fireball, AreaEffect)
+    assert fireball.centered_on_caster is False
+
+
+def test_bless_burst_is_centered_on_the_caster_not_the_target() -> None:
+    """Given: a caster at (0,0), an ally at (1,0) and a far ally at (11,11)
+    When: Bless is cast with the FAR ally as the resolved target
+    Then: the 50-ft burst opens on the caster: the near ally and the caster
+    are buffed, the far target (65 ft away, outside the burst) is not — the
+    chosen target does not move the origin (SRD bless.md)."""
+    caster = _state("caster", "players", (0, 0), caster=True, spells=("Bless",))
+    near = _state("near", "players", (1, 0))
+    far = _state("far", "players", (11, 11))
+    engine = _engine([], [caster, near, far])
+    engine._cast_spell(caster, far, "Bless")
+    assert _has_buff(caster, "Bless")
+    assert _has_buff(near, "Bless")
+    assert not _has_buff(far, "Bless")
+
+
+def test_bless_ignores_an_explicit_center_pos() -> None:
+    """Given: the same geometry
+    When: Bless is point-cast (U7b) with center_pos far from the caster
+    Then: the caster-centered flag wins — the burst still opens on the
+    caster ("centered on the caster" is not a chosen origin)."""
+    caster = _state("caster", "players", (0, 0), caster=True, spells=("Bless",))
+    near = _state("near", "players", (1, 0))
+    engine = _engine([], [caster, near])
+    engine._cast_spell(caster, near, "Bless", center_pos=(10, 10))
+    assert _has_buff(near, "Bless")
+
+
+def test_bane_affects_enemies_in_the_casters_burst_with_own_saves() -> None:
+    """Given: an enemy at (2,0) inside the caster's 50-ft burst and a far
+    enemy at (10,10) chosen as the resolved target
+    When: Bane is cast and the near enemy's Will save (the ONLY die in the
+    queue) succeeds
+    Then: there is no primary save on the far target (a centered burst has no
+    chosen origin — every creature in the area rolls its own); the near enemy
+    saves and takes nothing, the far enemy is outside the burst and rolls
+    nothing."""
+    caster = _state("caster", "players", (0, 0), caster=True, spells=("Bane",))
+    near = _state("near", "monsters", (2, 0))
+    far = _state("far", "monsters", (10, 10))
+    engine = _engine([20], [caster, near, far])
+    engine._cast_spell(caster, far, "Bane")
+    assert not _has_condition(near, "bane")
+    assert not _has_condition(far, "bane")
+    assert any("cast Bane vs far" in line and "NO SAVE" in line
+               for line in engine._transcript)
+
+
+def test_bane_failed_save_imposes_the_condition() -> None:
+    """Given: the same geometry
+    When: the near enemy fails its own Will save (d20=1, the only die)
+    Then: the bane condition lands on it — and the far target consumed no
+    primary die (the queue would be exhausted otherwise)."""
+    caster = _state("caster", "players", (0, 0), caster=True, spells=("Bane",))
+    near = _state("near", "monsters", (2, 0))
+    far = _state("far", "monsters", (10, 10))
+    engine = _engine([1], [caster, near, far])
+    engine._cast_spell(caster, far, "Bane")
+    assert _has_condition(near, "bane")
+    assert not _has_condition(far, "bane")
+
+
+def test_target_centered_burst_still_uses_the_target_cell() -> None:
+    """Contrast: Fireball (no centered_on_caster flag) still bursts on the
+    resolved target — the primary save and the origin are unchanged."""
+    caster = _state("caster", "players", (0, 0), caster=True,
+                    spells=("Fireball",))
+    enemy = _state("enemy", "monsters", (5, 0))
+    # Rolls: primary Reflex save (d20=1, fails), then the 6d6 damage dice
+    # (base 1d6 + 5 per caster level, CRB scaling) - the target-centered
+    # path is untouched by the centered_on_caster flag.
+    engine = _engine([1, 1, 1, 1, 1, 1, 1], [caster, enemy])
+    engine._cast_spell(caster, enemy, "Fireball")
+    assert enemy.hp < enemy.combatant.hp_max