diff --git a/game_rect.cpp b/game_rect.cpp
index a398db3d..8c04e59a 100644
--- a/game_rect.cpp
+++ b/game_rect.cpp
@@ -109,15 +109,6 @@ bool operator==(const game_rect& lhs, const game_rect& rhs) noexcept
   ;
 }
 
-game_rect& operator+=(game_rect& rect, const game_coordinat& delta) noexcept
-{
-  rect = game_rect(
-    rect.get_tl() + delta,
-    rect.get_br() + delta
-  );
-  return rect;
-}
-
 std::ostream& operator<<(std::ostream& os, const game_rect& r) noexcept
 {
   os << "(" << r.get_tl() << "-" << r.get_br() << ")";
diff --git a/piece.cpp b/piece.cpp
index a1f75411..d93c1ffa 100644
--- a/piece.cpp
+++ b/piece.cpp
@@ -268,6 +268,18 @@ void test_piece()
     const auto p{get_test_white_king()};
     assert(get_occupied_square(p) == square("e1"));
   }
+  // get_test_white_king
+  {
+    const auto p{get_test_white_king()};
+    assert(p.get_type() == piece_type::king);
+    assert(p.get_color() == chess_color::white);
+  }
+  // get_test_white_knight
+  {
+    const auto p{get_test_white_knight()};
+    assert(p.get_type() == piece_type::knight);
+    assert(p.get_color() == chess_color::white);
+  }
   // has_actions
   {
     const auto p{get_test_white_king()};
diff --git a/piece_action.cpp b/piece_action.cpp
index cc076c27..b69364f8 100644
--- a/piece_action.cpp
+++ b/piece_action.cpp
@@ -68,7 +68,7 @@ void test_piece_action()
     const piece_action a(piece_action_type::attack, square("e3"));
     assert(!to_str(piece_action(a)).empty());
     const piece_action b(piece_action_type::move, square("e2"), square("e4"));
-    assert(!to_str(piece_action(a)).empty());
+    assert(!to_str(piece_action(b)).empty());
   }
   // operator<<
   {
diff --git a/test_game.cpp b/test_game.cpp
index dfcecc21..c33aa114 100644
--- a/test_game.cpp
+++ b/test_game.cpp
@@ -67,6 +67,11 @@ void test_game_functions()
     g.add_action(create_press_left_action()); // cursor to d8
     g.tick();
     assert(!can_player_select_piece_at_cursor_pos(g, chess_color::white));
+
+    g.add_action(create_press_left_action()); // cursor to d7
+    g.add_action(create_press_left_action()); // cursor to d6
+    g.tick();
+    assert(!can_player_select_piece_at_cursor_pos(g, chess_color::white));
   }
   // clear_sound_effects
   {