1 files changed, 50 insertions, 0 deletions
diff --git a/internal/casino/blackjack_timer_test.go b/internal/casino/blackjack_timer_test.go
new file mode 100644
index 0000000..5a57682
--- /dev/null
+++ b/internal/casino/blackjack_timer_test.go
@@ -0,0 +1,50 @@
+package casino
+
+import "testing"
+
+// Regression: the blackjack action window may only restart when a new turn
+// is actually prompted. Rejected actions must never extend the deadline, and
+// each successive player must receive a full window.
+func TestBlackjackActionWindowBoundaries(t *testing.T) {
+	table := newBlackjackTable(1, TableConfig{ID: "blackjack", Game: GameBlackjack,
+		Blackjack: BlackjackConfig{ActionTicks: 3}}, newTestRand())
+	for _, name := range []string{"alice", "bob", "carol"} {
+		table.players.add(name, &blackjackPlayer{
+			Participant: Participant{Name: name, Connected: true, HasBet: true, Wallet: &testWallet{credits: 100}},
+			hands:       []*blackjackHand{{bet: 10, cards: []card{{rank: "10"}, {rank: "6"}}}},
+		})
+	}
+	table.dealer.cards = []card{{rank: "10"}, {rank: "7"}}
+	table.beginPlay()
+	table.prompt()
+
+	// Alice burns one tick, then submits an invalid action and one she cannot
+	// take (surrender disabled by default). Neither may reset her window.
+	table.tick()
+	table.action("alice", "invalid")
+	table.action("alice", "surrender")
+	if table.timer.clock != 1 {
+		t.Fatalf("rejected actions extended or reset the deadline: timer=%+v", table.timer)
+	}
+
+	// Two more ticks expire her window; the timeout advances to Bob.
+	table.tick()
+	table.tick()
+	if table.activeName() != "bob" {
+		t.Fatalf("timeout did not advance to bob: active=%s", table.activeName())
+	}
+	if table.timer.clock != 0 {
+		t.Fatalf("bob did not receive a fresh action window: timer=%+v", table.timer)
+	}
+
+	// Bob must survive two ticks and time out on the third.
+	table.tick()
+	table.tick()
+	if table.activeName() != "bob" {
+		t.Fatalf("bob timed out early: active=%s", table.activeName())
+	}
+	table.tick()
+	if table.activeName() != "carol" {
+		t.Fatalf("bob did not time out after his window: active=%s", table.activeName())
+	}
+}