fix(editor): fix target element index when creating/adding elements to frames (#11257)

packages/excalidraw/tests/clipboard.test.tsx

@@ -305,8 +305,88 @@ describe("pasting & frames", () => {
 
     await waitFor(() => {
       expect(h.elements.length).toBe(2);
+      expect(h.elements[0].type).toBe(rect.type);
+      expect(h.elements[0].frameId).toBe(frame.id);
+      expect(h.elements[1].id).toBe(frame.id);
+      expect(h.elements[0].index! < frame.index!).toBe(true);
+    });
+  });
+
+  it("should layer pasted elements above the highest frame child", async () => {
+    const frame = API.createElement({
+      type: "frame",
+      width: 100,
+      height: 100,
+      x: 0,
+      y: 0,
+    });
+    const frameChild = API.createElement({
+      id: "frameChild",
+      type: "rectangle",
+      x: 10,
+      y: 10,
+      width: 20,
+      height: 20,
+      frameId: frame.id,
+    });
+    const rect = API.createElement({ type: "rectangle" });
+
+    API.setElements([frameChild, frame]);
+
+    const clipboardJSON = await serializeAsClipboardJSON({
+      elements: [rect],
+      files: null,
+    });
+
+    mouse.moveTo(50, 50);
+
+    pasteWithCtrlCmdV(clipboardJSON);
+
+    await waitFor(() => {
+      expect(h.elements.length).toBe(3);
       expect(h.elements[1].type).toBe(rect.type);
       expect(h.elements[1].frameId).toBe(frame.id);
+      expect(h.elements.map((element) => element.id)).toEqual([
+        frameChild.id,
+        h.elements[1].id,
+        frame.id,
+      ]);
+      expect(h.elements[1].index! > frameChild.index!).toBe(true);
+      expect(h.elements[1].index! < frame.index!).toBe(true);
+    });
+  });
+
+  it("should preserve denormalized pasted frame child order", async () => {
+    const frame = API.createElement({
+      type: "frame",
+      width: 100,
+      height: 100,
+      x: 0,
+      y: 0,
+    });
+    const frameChild = API.createElement({
+      type: "rectangle",
+      x: 10,
+      y: 10,
+      width: 20,
+      height: 20,
+      frameId: frame.id,
+    });
+
+    const clipboardJSON = await serializeAsClipboardJSON({
+      elements: [frame, frameChild],
+      files: null,
+    });
+
+    mouse.moveTo(200, 200);
+
+    pasteWithCtrlCmdV(clipboardJSON);
+
+    await waitFor(() => {
+      expect(h.elements.length).toBe(2);
+      expect(h.elements[0].type).toBe(frame.type);
+      expect(h.elements[1].type).toBe(frameChild.type);
+      expect(h.elements[1].frameId).toBe(h.elements[0].id);
     });
   });
 
@@ -379,8 +459,9 @@ describe("pasting & frames", () => {
 
     await waitFor(() => {
       expect(h.elements.length).toBe(3);
-      expect(h.elements[1].type).toBe(rect.type);
-      expect(h.elements[1].frameId).toBe(frame.id);
+      expect(h.elements[0].type).toBe(rect.type);
+      expect(h.elements[0].frameId).toBe(frame.id);
+      expect(h.elements[1].id).toBe(frame.id);
       expect(h.elements[2].type).toBe(rect2.type);
       expect(h.elements[2].frameId).toBe(null);
     });
@@ -422,10 +503,11 @@ describe("pasting & frames", () => {
 
     await waitFor(() => {
       expect(h.elements.length).toBe(3);
-      expect(h.elements[1].type).toBe(rect.type);
+      expect(h.elements[0].type).toBe(rect.type);
+      expect(h.elements[0].frameId).toBe(frame.id);
+      expect(h.elements[1].type).toBe(rect2.type);
       expect(h.elements[1].frameId).toBe(frame.id);
-      expect(h.elements[2].type).toBe(rect2.type);
-      expect(h.elements[2].frameId).toBe(frame.id);
+      expect(h.elements[2].id).toBe(frame.id);
     });
   });
 
@@ -473,8 +555,9 @@ describe("pasting & frames", () => {
 
     await waitFor(() => {
       expect(h.elements.length).toBe(4);
-      expect(h.elements[1].type).toBe(rect.type);
-      expect(h.elements[1].frameId).toBe(frame.id);
+      expect(h.elements[0].type).toBe(rect.type);
+      expect(h.elements[0].frameId).toBe(frame.id);
+      expect(h.elements[1].id).toBe(frame.id);
       expect(h.elements[2].type).toBe(rect2.type);
       expect(h.elements[2].frameId).toBe(h.elements[3].id);
       expect(h.elements[3].type).toBe(frame2.type);