1 files changed, 35 insertions, 0 deletions
diff --git a/internal/game/login_throttle_test.go b/internal/game/login_throttle_test.go
new file mode 100644
index 0000000..b2565c4
--- /dev/null
+++ b/internal/game/login_throttle_test.go
@@ -0,0 +1,35 @@
+package game
+
+import (
+	"testing"
+	"time"
+)
+
+// TestLoginThrottleEscalatesAndResets pins the telnet login throttle: the
+// first wrong password is free, then the delay escalates to a cap, and a
+// successful login clears the state.
+func TestLoginThrottleEscalatesAndResets(t *testing.T) {
+	th := newLoginThrottle()
+	key := loginThrottleKey("alice", "203.0.113.7")
+
+	if d := th.delayFor(key); d != 0 {
+		t.Fatalf("first failure delay = %v, want 0", d)
+	}
+	if d := th.delayFor(key); d != 250*time.Millisecond {
+		t.Fatalf("second failure delay = %v, want 250ms", d)
+	}
+	if d := th.delayFor(key); d != 500*time.Millisecond {
+		t.Fatalf("third failure delay = %v, want 500ms", d)
+	}
+	for i := 0; i < 10; i++ {
+		th.delayFor(key)
+	}
+	if d := th.delayFor(key); d != loginThrottleMaxDelay {
+		t.Fatalf("capped delay = %v, want %v", d, loginThrottleMaxDelay)
+	}
+
+	th.clear(key)
+	if d := th.delayFor(key); d != 0 {
+		t.Fatalf("delay after clear = %v, want 0", d)
+	}
+}