Revision history: change sets + revisions + revert — the undo substrate (#48) (#61)

Co-authored-by: Steve Dudenhoeffer <[email protected]>

internal/service/gardens.go

@@ -140,7 +140,8 @@ func (s *Service) ListGardens(ctx context.Context, actorID int64) ([]domain.Gard
 // version mismatch it returns (current garden, ErrVersionConflict) so the handler
 // can return the fresh row for the client to rebase.
 func (s *Service) UpdateGarden(ctx context.Context, actorID, gardenID int64, in GardenInput, version int64) (*domain.Garden, error) {
-	if _, err := s.requireGardenRole(ctx, actorID, gardenID, roleOwner); err != nil {
+	before, err := s.requireGardenRole(ctx, actorID, gardenID, roleOwner)
+	if err != nil {
 		return nil, err
 	}
 	g, err := gardenFromInput(in, false) // no defaults: an update states every field
@@ -153,7 +154,18 @@ func (s *Service) UpdateGarden(ctx context.Context, actorID, gardenID int64, in
 	if updated != nil {
 		updated.MyRole = roleOwner.String() // only the owner reaches here
 	}
-	return updated, err
+	if err != nil {
+		return updated, err
+	}
+	// MyRole is computed, not stored; blank it in the snapshot so a revert can't
+	// write a role into a row that has no such column.
+	snap := *before
+	snap.MyRole = ""
+	after := *updated
+	after.MyRole = ""
+	s.record(ctx, gardenID, actorID, "Edited garden settings",
+		changeUpdate(domain.EntityGarden, gardenID, &snap, &after))
+	return updated, nil
 }
 
 // CopyGarden duplicates a garden into a new one owned by the actor, carrying