[lua] Test Image:flip() with sprite and without sprite (aseprite#3854)

src/app/script/image_class.cpp

@@ -26,6 +26,7 @@
 #include "app/util/autocrop.h"
 #include "app/util/resize_image.h"
 #include "base/fs.h"
+#include "doc/algorithm/flip_image.h"
 #include "doc/algorithm/flip_type.h"
 #include "doc/algorithm/shrink_bounds.h"
 #include "doc/cel.h"
@@ -585,12 +586,17 @@ int Image_flip(lua_State* L)
   auto obj = get_obj<ImageObj>(L, 1);
   doc::Image* img = obj->image(L);
   doc::algorithm::FlipType flipType = doc::algorithm::FlipType::FlipHorizontal;
-  if (lua_isinteger(L, 2) && lua_tointeger(L, 2) > 0)
-    flipType = doc::algorithm::FlipType::FlipVertical;
+  if (lua_isinteger(L, 2))
+    flipType = (doc::algorithm::FlipType)lua_tointeger(L, 2);
 
-  Tx tx;
-  tx(new cmd::FlipImage(img, img->bounds(), flipType));
-  tx.commit();
+  if (obj->cel(L) == nullptr) {
+    doc::algorithm::flip_image(img, img->bounds(), flipType);
+  }
+  else {
+    Tx tx;
+    tx(new cmd::FlipImage(img, img->bounds(), flipType));
+    tx.commit();
+  }
   return 0;
 }
 

tests/scripts/image.lua

@@ -405,8 +405,7 @@ do
 end
 
 -- Tests for Image:flip()
-do
-  local img = Image(3, 3)
+function test_image_flip(img)
   local r = Color(255, 0, 0).rgbaPixel
   local g = Color(0, 255, 0).rgbaPixel
   img:clear(0)
@@ -420,6 +419,10 @@ do
   expect_img(img, { 0, 0, g,
                     0, r, 0,
                     r, 0, 0 })
+
+  -- Without sprite, don't test undo
+  if not app.sprite then return end
+
   app.undo()
   expect_img(img, { g, 0, 0,
                     0, r, 0,
@@ -442,4 +445,9 @@ do
   expect_img(img, { g, 0, 0,
                     0, r, 0,
                     0, 0, r })
-end
+end
+
+local spr = Sprite(3, 3)   -- Test with sprite (with transactions & undo/redo)
+test_image_flip(app.image)
+app.sprite = nil           -- Test without sprite (without transactions)
+test_image_flip(Image(3, 3))