Improve targeting checks for cards that are not supposed to target anything

Fixes #141

Author: jleclanche

fireplace/targeting.py

@@ -4,6 +4,15 @@
 from .enums import CardType, PlayReq, Rarity
 
 
+TARGETING_PREREQUISITES = (
+	PlayReq.REQ_TARGET_TO_PLAY,
+	PlayReq.REQ_TARGET_FOR_COMBO,
+	PlayReq.REQ_TARGET_IF_AVAILABLE,
+	PlayReq.REQ_TARGET_IF_AVAILABLE_AND_DRAGON_IN_HAND,
+	PlayReq.REQ_TARGET_IF_AVAILABLE_AND_MINIMUM_FRIENDLY_MINIONS,
+)
+
+
 # Requirements-based targeting
 def is_valid_target(self, target, requirements=None):
 	if target is self:
@@ -28,6 +37,13 @@ def is_valid_target(self, target, requirements=None):
 	if requirements is None:
 		requirements = self.requirements
 
+	# Check if the entity can ever target other entities
+	for req in TARGETING_PREREQUISITES:
+		if req in requirements:
+			break
+	else:
+		return False
+
 	for req, param in requirements.items():
 		if req == PlayReq.REQ_MINION_TARGET:
 			if target.type != CardType.MINION:

tests/test_main.py

@@ -4844,15 +4844,21 @@ def test_force_of_nature():
 
 def test_warlock():
 	game = prepare_game(WARLOCK, WARLOCK)
+	game.player1.discard_hand()
+	assert not game.player1.hero.power.targets
+	assert game.player1.hero.power.is_usable()
+	game.player1.hero.power.use()
+	assert len(game.player1.hand) == 1
+	assert game.player1.hero.health == 28
+
 	sacpact = game.current_player.give("NEW1_003")
 	assert not sacpact.is_playable()
 	flameimp = game.current_player.give("EX1_319")
 	flameimp.play()
-	assert game.current_player.hero.health == 27
+	assert game.current_player.hero.health == 25
 	assert sacpact.is_playable()
 	sacpact.play(target=flameimp)
 	assert game.current_player.hero.health == 30
-	game.end_turn()
 
 
 def test_resurrect():