Add a regression test for searching another player's library

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: liamiak1

forge-gui-desktop/src/test/java/forge/game/ability/effects/SearchOwnLibraryTest.java

@@ -0,0 +1,76 @@
+package forge.game.ability.effects;
+
+import org.testng.annotations.Test;
+
+import forge.ai.AITest;
+import forge.game.Game;
+import forge.game.card.Card;
+import forge.game.phase.PhaseType;
+import forge.game.player.Player;
+import forge.game.spellability.SpellAbility;
+import forge.game.zone.ZoneType;
+
+import static junit.framework.Assert.assertEquals;
+
+/**
+ * Opposition Agent applies only while an opponent searches <i>their own</i> library, so searching
+ * someone else's must not hand the cards found to the Agent's controller.
+ */
+public class SearchOwnLibraryTest extends AITest {
+
+    @Test
+    public void agentIgnoresSearchesOfOtherPlayersLibraries() {
+        Game game = initAndCreateGame();
+        Player me = game.getPlayers().get(0);
+        Player opp = game.getPlayers().get(1);
+        addCard("Opposition Agent", me);
+
+        assertEquals("my own Acquire must still fetch for me", ZoneType.Battlefield,
+                acquireFrom(game, me, opp).getZone().getZoneType());
+
+        // and the case the card is for: the opponent tutoring out of their own library
+        Game other = initAndCreateGame();
+        Player agentOwner = other.getPlayers().get(0);
+        Player tutorer = other.getPlayers().get(1);
+        addCard("Opposition Agent", agentOwner);
+        assertEquals("their own tutor is still exiled by the Agent", ZoneType.Exile,
+                tutorFrom(other, tutorer).getZone().getZoneType());
+    }
+
+    /** Resolves Acquire cast by {@code me} at {@code opp}'s library, returning the Sol Ring. */
+    private Card acquireFrom(Game game, Player me, Player opp) {
+        Card solRing = stockLibrary(game, opp);
+        addCards("Island", 6, me);
+        SpellAbility sa = cast(game, addCardToZone("Acquire", me, ZoneType.Hand), me);
+        sa.getTargets().add(opp);
+        sa.resolve();
+        game.getAction().checkStateEffects(true);
+        return game.getCardState(solRing, solRing);
+    }
+
+    /** Resolves Diabolic Tutor cast by {@code tutorer} on their own library. */
+    private Card tutorFrom(Game game, Player tutorer) {
+        Card solRing = stockLibrary(game, tutorer);
+        addCards("Swamp", 6, tutorer);
+        cast(game, addCardToZone("Diabolic Tutor", tutorer, ZoneType.Hand), tutorer).resolve();
+        game.getAction().checkStateEffects(true);
+        return game.getCardState(solRing, solRing);
+    }
+
+    private Card stockLibrary(Game game, Player p) {
+        Card solRing = addCardToZone("Sol Ring", p, ZoneType.Library);
+        for (int i = 0; i < 5; i++) {
+            addCardToZone("Forest", p, ZoneType.Library);
+        }
+        return solRing;
+    }
+
+    private SpellAbility cast(Game game, Card c, Player p) {
+        game.getPhaseHandler().devModeSet(PhaseType.MAIN1, p);
+        game.getAction().checkStateEffects(true);
+        SpellAbility sa = c.getFirstSpellAbility();
+        sa.setActivatingPlayer(p);
+        sa.resetTargets();
+        return sa;
+    }
+}