1 files changed, 57 insertions, 0 deletions
diff --git a/internal/game/cmd_dig_test.go b/internal/game/cmd_dig_test.go
new file mode 100644
index 0000000..1a96c25
--- /dev/null
+++ b/internal/game/cmd_dig_test.go
@@ -0,0 +1,57 @@
+package game
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// TestFindNextRoomIDSkipsIDsInOtherDirectories: the in-game allocator must
+// check every room ID in the world, not just the current room's directory.
+// A directory-scoped scan hands out an ID that already exists elsewhere, and
+// World.AddRoomPath then silently shadows that room.
+func TestFindNextRoomIDSkipsIDsInOtherDirectories(t *testing.T) {
+	root := t.TempDir()
+	intro := filepath.Join(root, "intro")
+	arena := filepath.Join(root, "arena")
+	for _, dir := range []string{intro, arena} {
+		if err := os.MkdirAll(dir, 0o755); err != nil {
+			t.Fatal(err)
+		}
+	}
+	// intro owns 1001 and 1002; arena owns 1003.
+	for _, id := range []string{"1001", "1002"} {
+		if err := os.WriteFile(filepath.Join(intro, id+".yaml"), []byte("name: intro\n"), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := os.WriteFile(filepath.Join(arena, "1003.yaml"), []byte("name: arena\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	globallyUsed := map[int]bool{1001: true, 1002: true, 1003: true}
+
+	got, err := findNextRoomID(intro, globallyUsed)
+	if err != nil {
+		t.Fatalf("findNextRoomID: %v", err)
+	}
+	if got != 1004 {
+		t.Fatalf("findNextRoomID = %d, want 1004 (1003 is used by arena)", got)
+	}
+}
+
+// TestFindNextRoomIDEmptyDirectoryStartsAtOne: an empty directory still
+// allocates the globally lowest free ID rather than blindly returning 1.
+func TestFindNextRoomIDEmptyDirectoryStartsAtOne(t *testing.T) {
+	root := t.TempDir()
+	empty := filepath.Join(root, "empty")
+	if err := os.MkdirAll(empty, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	got, err := findNextRoomID(empty, map[int]bool{1: true, 2: true})
+	if err != nil {
+		t.Fatalf("findNextRoomID: %v", err)
+	}
+	if got != 3 {
+		t.Fatalf("findNextRoomID = %d, want 3", got)
+	}
+}