1 files changed, 186 insertions, 0 deletions
diff --git a/internal/game/production_output_regression_test.go b/internal/game/production_output_regression_test.go
new file mode 100644
index 0000000..cee028d
--- /dev/null
+++ b/internal/game/production_output_regression_test.go
@@ -0,0 +1,186 @@
+package game
+
+// Crafting-output regressions: a full inventory must never consume
+// materials without producing the output, and recipes whose entries share
+// the same item must reserve aggregate quantities (two one-ore entries need
+// two ore), never double-count one stack.
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"thehouseoficarus/internal/item"
+	"thehouseoficarus/internal/net"
+	"thehouseoficarus/internal/player"
+)
+
+const headlessArrowYAML = `id: headless_arrow
+name: headless arrow
+stackable: true
+value: 1
+craft:
+  - ingredients:
+      - items:
+          - arrow_shaft
+        quantity: 15
+      - items:
+          - feather
+        quantity: 15
+    level: 1
+    output_qty: 15
+    type: fletching
+    ticks_per_cycle: 2
+    xp: 1
+`
+
+func seedArrowWorld(t *testing.T, dir string) {
+	t.Helper()
+	seedWorld(t, dir)
+	defs := map[string]string{
+		"arrow_shaft":    "id: arrow_shaft\nname: arrow shaft\nstackable: true\nvalue: 1\n",
+		"feather":        "id: feather\nname: feather\nstackable: true\nvalue: 1\n",
+		"headless_arrow": headlessArrowYAML,
+	}
+	for id, data := range defs {
+		path := filepath.Join(dir, "items", id+".yaml")
+		if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(path, []byte(data), 0600); err != nil {
+			t.Fatal(err)
+		}
+	}
+}
+
+// TestFullInventoryFletchPreservesMaterials: a full inventory must refuse
+// the craft ("too full") WITHOUT consuming the ingredients — before the
+// fix, the 15-shaft/15-feather batch was consumed and the output silently
+// dropped.
+func TestFullInventoryFletchPreservesMaterials(t *testing.T) {
+	dir := t.TempDir()
+	seedArrowWorld(t, dir)
+	h := harnessFromDir(t, dir)
+	h.seedAccount("alice")
+	p := h.seedCharacter("alice", "alice")
+	h.g.RunOnOwner(func() {
+		p.SetInvSlot(0, &player.InventorySlot{ItemID: "arrow_shaft", Quantity: 30})
+		p.SetInvSlot(1, &player.InventorySlot{ItemID: "feather", Quantity: 30})
+		for i := 2; i < 28; i++ {
+			p.SetInvSlot(i, &player.InventorySlot{ItemID: "filler", Quantity: 1})
+		}
+		def, err := h.g.ItemStore.Load("headless_arrow")
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		if !h.g.canDoFletchItem(p, def) {
+			t.Error("recipe unexpectedly unavailable")
+			return
+		}
+		sess := &net.Session{Conn: newChanConn(), Player: p}
+		sess.SetState(net.StateGame)
+		h.g.startFletchAction(sess, p, def, 1)
+		// The timed fletch advances: phase 0 announces, phase 1 crafts.
+		h.g.advanceFletch(sess, p)
+		h.g.advanceFletch(sess, p)
+		if p.CountItem("arrow_shaft") != 30 || p.CountItem("feather") != 30 {
+			t.Errorf("materials consumed with no output: shafts=%d feathers=%d; want 30 each",
+				p.CountItem("arrow_shaft"), p.CountItem("feather"))
+		}
+		if p.CountItem("headless_arrow") != 0 {
+			t.Errorf("output produced into a full inventory: %d", p.CountItem("headless_arrow"))
+		}
+	})
+}
+
+// TestFullInventoryStackMergeStillCrafts: a full inventory may still craft
+// when the output merges into an existing stack.
+func TestFullInventoryStackMergeStillCrafts(t *testing.T) {
+	dir := t.TempDir()
+	seedArrowWorld(t, dir)
+	h := harnessFromDir(t, dir)
+	h.seedAccount("alice")
+	p := h.seedCharacter("alice", "alice")
+	h.g.RunOnOwner(func() {
+		p.SetInvSlot(0, &player.InventorySlot{ItemID: "arrow_shaft", Quantity: 30})
+		p.SetInvSlot(1, &player.InventorySlot{ItemID: "feather", Quantity: 30})
+		p.SetInvSlot(2, &player.InventorySlot{ItemID: "headless_arrow", Quantity: 5})
+		for i := 3; i < 28; i++ {
+			p.SetInvSlot(i, &player.InventorySlot{ItemID: "filler", Quantity: 1})
+		}
+		def, err := h.g.ItemStore.Load("headless_arrow")
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		sess := &net.Session{Conn: newChanConn(), Player: p}
+		sess.SetState(net.StateGame)
+		h.g.startFletchAction(sess, p, def, 1)
+		h.g.advanceFletch(sess, p)
+		h.g.advanceFletch(sess, p)
+		if got := p.CountItem("headless_arrow"); got != 20 {
+			t.Errorf("headless_arrow = %d, want 20 (5 existing + 15 new, merged)", got)
+		}
+		if p.CountItem("arrow_shaft") != 15 || p.CountItem("feather") != 15 {
+			t.Errorf("ingredients not consumed: shafts=%d feathers=%d", p.CountItem("arrow_shaft"), p.CountItem("feather"))
+		}
+	})
+}
+
+// TestOverlappingRecipeReservesAggregateStock: two ingredient entries
+// listing the same item cannot both consume one unit of it.
+func TestOverlappingRecipeReservesAggregateStock(t *testing.T) {
+	p := player.New("alice")
+	p.SetInvSlot(0, &player.InventorySlot{ItemID: "ore", Quantity: 1})
+	c := &item.CraftDef{Ingredients: []item.IngredientEntry{
+		{Items: []string{"ore"}, Quantity: 1},
+		{Items: []string{"ore"}, Quantity: 1},
+	}}
+	if craftHasAllItemsQty(c, p.CountItem) {
+		t.Error("one ore accepted for two one-ore entries")
+	}
+	if consumeIngredients(c, p.CountItem, p.RemoveItem) {
+		t.Error("consumption reports success despite insufficient aggregate stock")
+	}
+	if p.CountItem("ore") != 1 {
+		t.Error("a refused recipe removed partial materials")
+	}
+}
+
+// TestOverlappingRecipeReservesAcrossEntries: reservations apply across
+// differing alternative lists — two one-water entries need TWO water-like
+// items, and the plan consumes distinct ones, never one twice.
+func TestOverlappingRecipeReservesAcrossEntries(t *testing.T) {
+	// Only one water-carrying item: the second entry cannot be satisfied.
+	p := player.New("alice")
+	p.SetInvSlot(0, &player.InventorySlot{ItemID: "clay", Quantity: 1})
+	p.SetInvSlot(1, &player.InventorySlot{ItemID: "bucket_of_water", Quantity: 1})
+	c := &item.CraftDef{Ingredients: []item.IngredientEntry{
+		{Items: []string{"clay"}, Quantity: 1},
+		{Items: []string{"water", "bucket_of_water"}, Quantity: 1},
+		{Items: []string{"bucket_of_water", "water"}, Quantity: 1},
+	}}
+	if planIngredients(c, p.CountItem) != nil {
+		t.Error("one water unit accepted for two one-water entries")
+	}
+	if p.CountItem("clay") != 1 || p.CountItem("bucket_of_water") != 1 {
+		t.Error("availability planning mutated inventory")
+	}
+
+	// Both water items present: the plan consumes each exactly once.
+	p.SetInvSlot(2, &player.InventorySlot{ItemID: "water", Quantity: 1})
+	plan := planIngredients(c, p.CountItem)
+	if plan == nil {
+		t.Fatal("clay + bucket + water must satisfy the recipe")
+	}
+	chosen := map[string]int{}
+	for _, s := range plan {
+		chosen[s.id]++
+	}
+	for id, want := range map[string]int{"clay": 1, "bucket_of_water": 1, "water": 1} {
+		if chosen[id] != want {
+			t.Errorf("plan chose %s %d times, want %d (plan=%+v)", id, chosen[id], want, plan)
+		}
+	}
+}