fix: Inserting link removes comment

packages/core/src/editor/managers/StyleManager.ts

@@ -169,7 +169,12 @@ export class StyleManager<
       const { from, to } = tr.selection;
 
       if (text) {
-        tr.insertText(text, from, to).addMark(from, from + text.length, mark);
+        const existingText = tr.doc.textBetween(from, to);
+        if (text !== existingText) {
+          tr.insertText(text, from, to);
+        }
+
+        tr.addMark(from, from + text.length, mark);
       } else {
         tr.setSelection(TextSelection.create(tr.doc, to)).addMark(
           from,

packages/core/src/extensions/LinkToolbar/LinkToolbar.ts

@@ -88,7 +88,12 @@ export const LinkToolbarExtension = createExtension(({ editor }) => {
         if (!range) {
           return;
         }
-        tr.insertText(text, range.from, range.to);
+
+        const existingText = tr.doc.textBetween(range.from, range.to);
+        if (text !== existingText) {
+          tr.insertText(text, range.from, range.to);
+        }
+
         tr.addMark(
           range.from,
           range.from + text.length,

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

@@ -0,0 +1,50 @@
+import { expect } from "@playwright/test";
+import { test } from "../../setup/setupScript.js";
+import { BASE_URL, LINK_BUTTON_SELECTOR } from "../../utils/const.js";
+import { focusOnEditor } from "../../utils/editor.js";
+
+test.beforeEach(async ({ page }) => {
+  await page.goto(BASE_URL);
+});
+
+test.describe("Check Link Toolbar functionality", () => {
+  test("Should preserve existing marks when editing a link", async ({
+    page,
+  }) => {
+    await focusOnEditor(page);
+
+    // Type bold text
+    await page.keyboard.type("hello");
+    await page.keyboard.press("Shift+Home");
+
+    // Make it bold via formatting toolbar
+    await page.waitForSelector(`[data-test="bold"]`);
+    await page.click(`[data-test="bold"]`);
+
+    // Add link
+    await page.keyboard.press("Shift+Home");
+    await page.waitForSelector(LINK_BUTTON_SELECTOR);
+    await page.click(LINK_BUTTON_SELECTOR);
+    await page.keyboard.type("https://example.com");
+    await page.keyboard.press("Enter");
+
+    // Move cursor back onto the linked text to trigger link toolbar
+    await page.keyboard.press("ArrowLeft");
+    await page.waitForTimeout(500);
+
+    // Click Edit link button
+    const editButton = page.getByText("Edit link");
+    await editButton.waitFor({ state: "visible" });
+    await editButton.click();
+
+    await page.keyboard.press("Control+A");
+    await page.keyboard.type("https://example2.com");
+    await page.keyboard.press("Enter");
+
+    await page.waitForTimeout(300);
+
+    // Verify bold mark is still present on the text
+    const boldText = page.locator("strong a, a strong");
+    await expect(boldText).toBeVisible();
+  });
+});