1 files changed, 149 insertions, 0 deletions
diff --git a/internal/admin/api_room_rename_test.go b/internal/admin/api_room_rename_test.go
new file mode 100644
index 0000000..8d273f4
--- /dev/null
+++ b/internal/admin/api_room_rename_test.go
@@ -0,0 +1,149 @@
+package admin
+
+// Room-rename mutation-plan regressions: the rename, the reference rewrites
+// (including self-loops), the runtime migration callback, undo, redo, and
+// injected partial-write failures must all agree.
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func renameRoom(t *testing.T, s *AdminServer, id, newID int) *httptest.ResponseRecorder {
+	t.Helper()
+	body, _ := json.Marshal(map[string]int{"id": id, "new_id": newID})
+	req := httptest.NewRequest(http.MethodPost, "/api/room/rename", strings.NewReader(string(body)))
+	rec := httptest.NewRecorder()
+	s.handleRoomRename(rec, req)
+	return rec
+}
+
+func roomBody(t *testing.T, s *AdminServer, id int) string {
+	t.Helper()
+	path, ok := s.world.GetRoomPath(id)
+	if !ok {
+		return ""
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(data)
+}
+
+// TestRoomRenameFullPlanCoversReferencesAndSelfLoop: renaming a room that a
+// neighbor references and that references itself rewrites the neighbor, the
+// renamed room's own id field AND self-loop, moves the file, and records the
+// whole plan for undo.
+func TestRoomRenameFullPlan(t *testing.T) {
+	s := newTestAdminServer(t, map[int]string{
+		5: "id: 5\nname: Lab\nexits:\n  north:\n    room: 6\n  east:\n    room: 5\n",
+		6: "id: 6\nname: Hall\nexits:\n  south:\n    room: 5\n",
+	})
+
+	var migrated []map[int]int
+	// The wired callback mirrors production (the game's MigrateRoomIDs):
+	// record the map and rebuild the world room index after migration.
+	migrate := func(idMap map[int]int) {
+		recorded := map[int]int{}
+		for k, v := range idMap {
+			recorded[k] = v
+		}
+		migrated = append(migrated, recorded)
+		s.world.RebuildRoomIndex(s.dataDir)
+	}
+	s.rewriteRoomIDs = migrate
+	s.undoStack.SetMigrateRoomIDs(migrate)
+
+	rec := renameRoom(t, s, 5, 7)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("rename failed: %d %s", rec.Code, rec.Body.String())
+	}
+
+	// Renamed room file: moved, id field rewritten, self-loop corrected.
+	selfBody := roomBody(t, s, 7)
+	if !strings.Contains(selfBody, "room: 7") {
+		t.Fatalf("renamed room self-loop not rewritten: %q", selfBody)
+	}
+	if _, err := os.Stat(filepath.Join(s.dataDir, "rooms", "5.yaml")); !os.IsNotExist(err) {
+		t.Fatalf("old room file still exists: %v", err)
+	}
+	// The referencing room's exit moved.
+	hallBody := roomBody(t, s, 6)
+	if !strings.Contains(hallBody, "room: 7") {
+		t.Fatalf("reference rewrite missing: %q", hallBody)
+	}
+	// The runtime migration callback ran with the forward map.
+	if len(migrated) != 1 {
+		t.Fatalf("runtime migration callback not invoked with one plan: %v", migrated)
+	}
+
+	// Undo: everything returns to before-images, inverse migration runs.
+	if s.undoStack.Undo() == nil {
+		t.Fatal("undo failed")
+	}
+	if roomBody(t, s, 5) == "" {
+		t.Fatal("undo did not restore the renamed room at its old path")
+	}
+	if _, err := os.Stat(filepath.Join(s.dataDir, "rooms", "7.yaml")); !os.IsNotExist(err) {
+		t.Fatalf("undo left the new room file behind: %v", err)
+	}
+	if hall := roomBody(t, s, 6); strings.Contains(hall, "room: 7") {
+		t.Fatalf("undo did not restore the referencing room: %q", hall)
+	}
+	// The last migration callback must be the inverse map.
+	if last := migrated[len(migrated)-1]; !(len(last) == 1 && last[7] == 5) {
+		t.Fatalf("undo migration callback = %v, want inverse {7:5}", last)
+	}
+
+	// Redo: forward again, whole plan re-applied.
+	if s.undoStack.Redo() == nil {
+		t.Fatal("redo failed")
+	}
+	if !strings.Contains(roomBody(t, s, 6), "room: 7") {
+		t.Fatal("redo did not re-apply the reference rewrite")
+	}
+	if roomBody(t, s, 5) != "" {
+		t.Fatal("redo resurrected the old room file")
+	}
+	if last := migrated[len(migrated)-1]; !(len(last) == 1 && last[5] == 7) {
+		t.Fatalf("redo migration callback = %v, want forward {5:7}", last)
+	}
+}
+
+// TestRoomRenameAbortsOnWriteFailure: when the write side fails mid-plan,
+// the journal transaction rolls back — the old room file and its references
+// stay untouched, and no half-renamed state survives.
+func TestRoomRenameAbortsOnWriteFailure(t *testing.T) {
+	s := newTestAdminServer(t, map[int]string{
+		5: "id: 5\nname: Lab\nexits:\n  north:\n    room: 6\n",
+		6: "id: 6\nname: Hall\nexits:\n  south:\n    room: 5\n",
+	})
+
+	// A read-only rooms directory makes every room-file write fail.
+	roomsDir := filepath.Join(s.dataDir, "rooms")
+	if err := os.Chmod(roomsDir, 0500); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { os.Chmod(roomsDir, 0700) })
+
+	rec := renameRoom(t, s, 5, 7)
+	if rec.Code == http.StatusOK {
+		t.Fatalf("rename succeeded despite the write failure: %s", rec.Body.String())
+	}
+	os.Chmod(roomsDir, 0700)
+
+	// Nothing was renamed: room 5 still exists at its old path with its
+	// original content, and room 7 does not exist.
+	if body := roomBody(t, s, 5); !strings.Contains(body, "id: 5") {
+		t.Fatalf("room 5 damaged by failed rename: %q", body)
+	}
+	if roomExists(s, 7) {
+		t.Fatal("room 7 exists after the failed rename")
+	}
+}