1 files changed, 105 insertions, 0 deletions
diff --git a/internal/game/hardening_credit_cap_test.go b/internal/game/hardening_credit_cap_test.go
new file mode 100644
index 0000000..872c746
--- /dev/null
+++ b/internal/game/hardening_credit_cap_test.go
@@ -0,0 +1,105 @@
+package game
+
+// Regression: credit pickups must never destroy value at the economy cap.
+// Only the balance headroom below casino.MaxCredits may be removed from the
+// ground; the remainder stays there. The previous code removed the whole
+// ground stack and then let grantCredits clamp the excess away.
+
+import (
+	"strings"
+	"testing"
+
+	"thehouseoficarus/internal/casino"
+	"thehouseoficarus/internal/net"
+)
+
+func TestPickupCreditsAtCapLeavesRemainderOnGround(t *testing.T) {
+	h := newHarness(t)
+	h.seedAccount("alice")
+	p := h.seedCharacter("alice", "alice")
+	h.g.RunOnOwner(func() {
+		p.Credits = casino.MaxCredits - 5
+		h.g.World.AddGroundItem(p.RoomID, "credits", 20)
+		sess := &net.Session{Conn: newChanConn(), Player: p}
+		sess.SetState(net.StateGame)
+
+		h.g.pickupCredits(sess, p, "credits")
+
+		if p.Credits != casino.MaxCredits {
+			t.Errorf("balance = %d, want the cap %d", p.Credits, casino.MaxCredits)
+		}
+		if got := h.g.World.GroundItems(p.RoomID)["credits"]; got != 15 {
+			t.Errorf("ground credits = %d, want 15 left behind", got)
+		}
+	})
+}
+
+func TestPickupCreditsAtCapDestroysNothing(t *testing.T) {
+	h := newHarness(t)
+	h.seedAccount("alice")
+	p := h.seedCharacter("alice", "alice")
+	h.g.RunOnOwner(func() {
+		p.Credits = casino.MaxCredits
+		h.g.World.AddGroundItem(p.RoomID, "credits", 20)
+		sess := &net.Session{Conn: newChanConn(), Player: p}
+		sess.SetState(net.StateGame)
+
+		h.g.pickupCredits(sess, p, "credits")
+
+		if p.Credits != casino.MaxCredits {
+			t.Errorf("balance = %d, want the cap %d", p.Credits, casino.MaxCredits)
+		}
+		if got := h.g.World.GroundItems(p.RoomID)["credits"]; got != 20 {
+			t.Errorf("ground credits = %d, want the full stack to survive", got)
+		}
+		if out := string(sess.Conn.(*chanConn).Bytes()); !strings.Contains(out, "can't hold any more credits") {
+			t.Errorf("expected a cap message, got %q", out)
+		}
+	})
+}
+
+func TestGetAllCreditsAtCapLeavesRemainderOnGround(t *testing.T) {
+	h := newHarness(t)
+	h.seedAccount("alice")
+	p := h.seedCharacter("alice", "alice")
+	h.g.RunOnOwner(func() {
+		p.Credits = casino.MaxCredits - 5
+		h.g.World.AddGroundItem(p.RoomID, "credits", 20)
+		sess := &net.Session{Conn: newChanConn(), Player: p}
+		sess.SetState(net.StateGame)
+
+		h.g.doGetAll(sess)
+
+		if p.Credits != casino.MaxCredits {
+			t.Errorf("balance = %d, want the cap %d", p.Credits, casino.MaxCredits)
+		}
+		if got := h.g.World.GroundItems(p.RoomID)["credits"]; got != 15 {
+			t.Errorf("ground credits = %d, want 15 left behind", got)
+		}
+	})
+}
+
+func TestGetAllCreditsAtCapReportsShortfall(t *testing.T) {
+	h := newHarness(t)
+	h.seedAccount("alice")
+	p := h.seedCharacter("alice", "alice")
+	h.g.RunOnOwner(func() {
+		p.Credits = casino.MaxCredits
+		h.g.World.AddGroundItem(p.RoomID, "credits", 20)
+		sess := &net.Session{Conn: newChanConn(), Player: p}
+		sess.SetState(net.StateGame)
+
+		h.g.doGetAll(sess)
+
+		if got := h.g.World.GroundItems(p.RoomID)["credits"]; got != 20 {
+			t.Errorf("ground credits = %d, want the full stack to survive", got)
+		}
+		out := string(sess.Conn.(*chanConn).Bytes())
+		if !strings.Contains(out, "can't hold any more credits") {
+			t.Errorf("expected a cap message, got %q", out)
+		}
+		if strings.Contains(out, "inventory is full") {
+			t.Errorf("cap shortfall misreported as a full inventory: %q", out)
+		}
+	})
+}