fix(tests): stabilize webkit keyboard handler tests with programmatic cursor positioning (#2746)

ArrowUp in WebKit (especially Linux) can position the cursor incorrectly
when crossing blocks with different indentation levels, causing Delete/
Backspace tests to fail intermittently. Replace unreliable keyboard
navigation (ArrowUp, Control+ArrowLeft, ControlOrMeta+ArrowLeft/Right)
with programmatic cursor positioning via BlockNote's
setTextCursorPosition API.

Author: nperez0111

tests/src/end-to-end/keyboardhandlers/keyboardhandlers.test.ts

@@ -5,7 +5,12 @@ import {
   ITALIC_BUTTON_SELECTOR,
 } from "../../utils/const.js";
 import { insertHeading, insertParagraph } from "../../utils/copypaste.js";
-import { compareDocToSnapshot, focusOnEditor } from "../../utils/editor.js";
+import {
+  compareDocToSnapshot,
+  focusOnEditor,
+  moveCursorToBlockEnd,
+  moveCursorToBlockStart,
+} from "../../utils/editor.js";
 import { executeSlashCommand } from "../../utils/slashmenu.js";
 
 test.describe.configure({ mode: "serial" });
@@ -96,7 +101,7 @@ test.describe("Check Keyboard Handlers' Behaviour", () => {
     await focusOnEditor(page);
     await insertHeading(page, 1);
 
-    await page.keyboard.press("Control+ArrowLeft");
+    await moveCursorToBlockStart(page);
     await page.keyboard.press("Backspace");
 
     await compareDocToSnapshot(page, "backspaceStartOfBlock.json");
@@ -143,7 +148,7 @@ test.describe("Check Keyboard Handlers' Behaviour", () => {
       await page.keyboard.press("ArrowUp");
     }
 
-    await page.keyboard.press("Control+ArrowLeft");
+    await moveCursorToBlockStart(page);
     await page.keyboard.press("Backspace");
 
     await compareDocToSnapshot(page, "backspacePreservesNestedBlocks.json");
@@ -283,6 +288,7 @@ test.describe("Check Keyboard Handlers' Behaviour", () => {
 
     await page.keyboard.press("ArrowUp");
     await page.keyboard.press("ArrowUp");
+    await moveCursorToBlockEnd(page);
     await page.keyboard.press("Delete");
 
     await compareDocToSnapshot(page, "deleteMultipleChildren.json");
@@ -299,6 +305,7 @@ test.describe("Check Keyboard Handlers' Behaviour", () => {
 
     await page.keyboard.press("ArrowUp");
     await page.keyboard.press("ArrowUp");
+    await moveCursorToBlockEnd(page);
     await page.keyboard.press("Delete");
 
     await compareDocToSnapshot(page, "deleteNestedChildren.json");
@@ -314,6 +321,7 @@ test.describe("Check Keyboard Handlers' Behaviour", () => {
     await insertParagraph(page);
 
     await page.keyboard.press("ArrowUp");
+    await moveCursorToBlockEnd(page);
     await page.keyboard.press("Delete");
 
     await compareDocToSnapshot(page, "deleteShallowerBlock.json");
@@ -335,8 +343,7 @@ test.describe("Check Keyboard Handlers' Behaviour", () => {
 
     await page.keyboard.press("ArrowUp");
     await page.keyboard.press("ArrowUp");
-    await page.keyboard.press("ControlOrMeta+ArrowLeft");
-    await page.keyboard.press("ControlOrMeta+ArrowRight");
+    await moveCursorToBlockEnd(page);
     await page.keyboard.press("Delete");
 
     await compareDocToSnapshot(page, "deleteShallowerBlockWithChildren.json");

tests/src/utils/editor.ts

@@ -46,3 +46,32 @@ export async function compareDocToSnapshot(page: Page, name: string) {
   const doc = JSON.stringify(await getDoc(page), null, 2);
   expect(doc).toMatchSnapshot(`${name}.json`);
 }
+
+/**
+ * Programmatically move cursor to end of the current block content.
+ * This avoids relying on keyboard navigation (ArrowUp/End) which can
+ * position the cursor incorrectly in WebKit when crossing blocks with
+ * different indentation levels.
+ */
+export async function moveCursorToBlockEnd(page: Page) {
+  await page.evaluate(() => {
+    const tiptap = (window as any).ProseMirror;
+    const bnEditor = tiptap.schema.cached.blockNoteEditor;
+    const block = bnEditor.getTextCursorPosition().block;
+    bnEditor.setTextCursorPosition(block, "end");
+  });
+}
+
+/**
+ * Programmatically move cursor to start of the current block content.
+ * This avoids relying on keyboard navigation which can be unreliable
+ * in WebKit.
+ */
+export async function moveCursorToBlockStart(page: Page) {
+  await page.evaluate(() => {
+    const tiptap = (window as any).ProseMirror;
+    const bnEditor = tiptap.schema.cached.blockNoteEditor;
+    const block = bnEditor.getTextCursorPosition().block;
+    bnEditor.setTextCursorPosition(block, "start");
+  });
+}