Add test to guard against break in undo / redo

browser_tests/changeTracker.spec.ts

@@ -53,6 +53,29 @@ test.describe('Change Tracker', () => {
     })
   })
 
+  test('Can undo & redo user changes', async ({ comfyPage }) => {
+    comfyPage.clickEmptySpace()
+    await expect(comfyPage.canvas).toHaveScreenshot('undo-initial-state.png')
+
+    comfyPage.dragAndDrop(
+      comfyPage.clipTextEncodeNode2OutputSlot,
+      comfyPage.kSamplerTitlebar
+    )
+    await expect(comfyPage.canvas).toHaveScreenshot('undo-step1.png')
+
+    comfyPage.ctrlZ()
+    await expect(comfyPage.canvas).toHaveScreenshot('undo-step2.png')
+
+    comfyPage.dragAndDrop(
+      comfyPage.clipTextEncodeNode1OutputSlot,
+      comfyPage.kSamplerTitlebar
+    )
+    await expect(comfyPage.canvas).toHaveScreenshot('undo-step3.png')
+
+    comfyPage.ctrlZ()
+    await expect(comfyPage.canvas).toHaveScreenshot('undo-step4.png')
+  })
+
   test('Can group multiple change actions into a single transaction', async ({
     comfyPage
   }) => {

browser_tests/fixtures/ComfyPage.ts

@@ -458,10 +458,20 @@ export class ComfyPage {
   get clipTextEncodeNode1InputSlot(): Position {
     return { x: 427, y: 198 }
   }
+  get clipTextEncodeNode1OutputSlot(): Position {
+    return { x: 828, y: 197 }
+  }
 
   get clipTextEncodeNode2InputSlot(): Position {
     return { x: 422, y: 402 }
   }
+  get clipTextEncodeNode2OutputSlot(): Position {
+    return { x: 828, y: 400 }
+  }
+
+  get kSamplerTitlebar(): Position {
+    return { x: 1058, y: 175 }
+  }
 
   // A point on input edge.
   get clipTextEncodeNode2InputLinkPath(): Position {